 The Joslin Clinical Nutrition Guideline for Overweight and Obese Adults With Type 2 Diabetes (T2D) or Prediabetes, or Those at High Risk for Developing T2D is designed to assist primary care physicians, specialists, and other healthcare providers in individualizing the care of and setting goals for adult, nonpregnant patients with T2D or individuals at high risk for developing the disease. This guideline focuses on the unique needs of those individuals. Several components complement the 2015-2020 Dietary Guidelines for Americans. The Dietary Guidelines for Americansare jointly developed every 5 years by the US Department of Health and Human Services and the US Department of Agriculture. This Guideline is not intended to replace sound medical judgment or clinical decision making and may need to be adapted for certain patient-care situations where more or less stringent interventions are necessary. This guideline was approved October 19, 2016; updated on January 28, 2018.

TABLE 1. Individuals Targeted for Intervention Meet 1 Criterion in Each of 2 Categories

There is strong evidence that weight reduction improves insulin sensitivity and glycemic control, lipid profile, and blood pressure in T2D, and decreases the risk of developing T2D in prediabetes and high-risk populations [1A].

Refer individuals to a registered dietitian (RD) experienced in diabetes and weight management for individualized medical nutrition therapy (MNT); care should be coordinated with an interdisciplinary team including the patient’s primary care physi- cian (PCP) [1B].	

To enhance effectiveness of MNT, a series of 3 to 4 encounters with an RD, each lasting 45 to 90 minutes, is recommended to begin at diagnosis

Glycemic control as well as achieving blood pressure and low-density lipoprotein cholesterol goals

Meal-to-meal consistency in carbohydrate distribution for those with fixed medication/ insulin programs

Individualization for cultural and food preferences (eg, vegetarian)

Adoption of a healthy eating pattern that is sustainable over time. The Mediterranean diet, the DASH [Dietary Approaches to Stop Hypertension] diet, and a plant-based or vegetarian diet are examples of healthy dietary patterns

Integration of behavior-change therapies to adopt healthy eating behaviors and sustainable weight loss

The meal plan composition, described below, is for general guidance only and may be individualized by the RD or other healthcare provider according to clinical judgment, individual (patient) preferences and needs, and metabolic response.

Physical activity is an integral component of a weight loss program for both initial weight loss and for weight maintenance.

A structured lifestyle plan that combines dietary modification, activity, and behavioral modification, along with ongoing support, is necessary for weight reduction [1B]. To maintain long-term weight loss, ongoing weight-maintenance counseling and support is recommended.

A modest and gradual weight reduction of 1 to 2 pounds every 1 to 2 weeks should be the optimal target [2A]. Reduction of daily caloric intake should be between 250-750 calories [1C]. Total daily intake should not be less than 1000 to 1200 calories for women and 1200 to 1600 calories for men, or based on an RD assessment of usual intake [1C].

A 5% to 10% weight loss may result in significant improvement in blood glucose control among patients with diabetes and may help prevent the onset of diabetes among individuals with prediabetes [1B]. Weight reduction should be individualized and continued until an agreed-upon BMI and/or other metabolic goals are reached.

Target individuals should meet with an RD to discuss a structured MNT plan for weight management that includes menus and snacks as well as education and practice in portion control, all effective components of weight-management plans [1B].

Diabetes-Specific Meal Replacements (DSMRs) in the form of shakes, bars, ready-to-mix powders, and prepackaged meals that match these nutrition guidelines may be effective in initiating and maintaining weight loss.	

Meal replacements should be used under the supervision of a RD

When meal replacements are initiated, glucose levels should be carefully monitored and, if needed, antihyperglycemic medications should be adjusted

Meal replacements should be used with caution by those with hyperkalemia

Bariatric surgeries, although not without medical and nutrition risks, are effective options and may be discussed when indicated (consider in individuals with BMI ≥40 kg/m

 with other comorbidities. Reduce calculations by 2.5 kg/m

 for Asians) [2B]. To date, there is limited evidence to support the recommendation of bariatric surgeries for patients with BMI <35 kg/m

 even if a person has diabetes or other comorbid conditions.

Anti-obesity medications may be considered for patients who were not able to lose weight through lifestyle modifications, but the long-term risks and benefits of these medications are unclear [2C].

The effect of diabetes medications should be evaluated throughout the weight loss program and adjusted as necessary to avoid hypoglycemia.

 There is general agreement that the type of fat consumed is more important than the quantity (generally 30% to 40% of total calories). Trans fats from partially hydrogenated oil should be eliminated [1B].

Monounsaturated and polyunsaturated fats should comprise the majority of fat intake [2B].

Limit saturated fat intake to <10% of total calories.	

Recent evidence demonstrates that saturated fat from dairy foods (milk, yogurt, cheese) may be acceptable within the total daily caloric intake [2B] 

Despite recent evidence suggesting that saturated fat poses a weak or neutral effect on health, further research in this area is warranted

Low-fat diets are generally less effective than low- carbohydrate diets for weight reduction [2C]

Plant fats rich in mono- and polyunsaturated fats (eg, olive oil, canola oil, soybean oil, nuts/seeds, and avocado) [2A]

Oily fish rich in omega-3 fatty acids (eg, salmon, herring, trout, sardines, fresh tuna) 2 times/week, as a source of these fatty acids [2B]

Foods high in saturated animal fat, including nonlean pork, lamb, and beef; processed meat; butter and cream

Foods high in trans fats (eg, most fast foods; most commercially baked goods; margarines from partially hydrogenated oil)

 Protein intake should range between 1.0-1.5 grams/kg of adjusted body weight. To calculate adjusted body weight, first calculate excess weight: Excess weight = current weight — ideal body weight (IBW). Adjusted body weight = IBW + 0.25 of excess body weight. This amount generally accounts for 20% to 30% of total caloric intake.

A modest increase in protein reduces appetite and helps achieve and maintain weight reduction [2B]. Protein also helps minimize loss of lean body mass during weight reduction [2B].

No reliable scientific data support a protein intake that exceeds 2 grams/kg of adjusted body weight. Conversely, reduction of protein intake to less than 0.8 grams/kg day may result in protein malnutrition.

Fish, skinless poultry, lean meat, dairy, egg whites, nuts, seeds, soy, and other legumes [2B].

Sources of protein that are high in saturated fat (eg nonlean pork, lamb, beef; processed meats) as they may be associated with increased cardiovascular risk[1B]. Heme iron in meat is also associated with an increased risk of T2D [2B].

 Although reducing total calories may result in a reduction of the total amount of protein intake, any patient with signs of kidney disease (both of the following: proteinuria; estimated glomular filtration rate <60 ml/min) should consult a nephrologist before increasing the total or percentage of protein in their diet [1B]. Protein intake for these patients should be modified, but not lowered to a level that may jeopardize their overall health or increase their risk for malnutrition or hypoalbuminemia.

 The total daily intake of carbohydrate should be at least 130 grams/day and preferably 40% to 45% of the total caloric intake. Intake should be adjusted to meet the cultural and food preferences of the individual.

Consideration of glycemic index/glycemic load.

 The glycemic index/glycemic load is an important factor that patients should apply in their daily selection of carbohydrate foods. Foods with a lower glycemic index content should be selected [2B] (eg, whole grains, legumes, fruits, green leafy and nonstarchy vegetables, milk, yogurt).

Green leafy and nonstarchy vegetables, whole fruits, legumes, whole and minimally processed grains, oats, milk, yogurt [2B].

Sugar, or added sugar, especially sugar-sweetened beverages, ice cream, candies, and grain-based desserts. Milk chocolate should be avoided.

Refined grain products including white bread, white pasta, white rice, low-fiber wheat cereal, cakes, muffins, pizza. White bagels should be limited.

High glycemic-index carbohydrates, including white potatoes and white rice.

Approximately 14 grams of fiber/1000 cal (20-35 grams) per day is recommended [1C]. If tolerated, approximately 50 grams/day is effective in improving postprandial hyperglycemia; that quantity should be encouraged [2B].

Fiber from unprocessed plant-based food, such as vegetables, fruits, seeds, nuts, and legumes, is preferable. However, if needed, fiber supplements such as psyllium, resistant starch, and β-glucan can be added [2B].

 Daily consumption should be <2300 mg (about 1 tsp of salt) per day [1A]. Further reduction to 1500 mg is recommended in people aged >50 years, especially those including those with hypertension or chronic kidney disease [2B].

Daily consumption should be a minimum of 4700 mg unless potassium excretion is impaired (eg, patients with chronic kidney disease; patients on certain drugs who retain potassium).

Potassium helps offset high sodium intake by triggering more sodium excretion by the kidneys.

Potassium-rich foods include fruits and vegetables like bananas, mushrooms, spinach, and almonds.

In individuals who are not deficient, there are no significant data supporting the routine use of vitamins or minerals to improve glucose control. However, some individuals may benefit from multivitamin supplementation, as calorie-restricted diets may be inadequate in some nutrients, such as calcium.

No significant data support the use of herbal supplements or spices to improve glucose control.

All FDA-approved nonnutritive sweeteners are permissible in moderate quantities.

If alcohol is consumed, consumption must remain moderate: no more than 1 drink per day for women and no more than 2 drinks per day for men (1 drink is equal to 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of 80-proof distilled alcohol).

Alcoholic beverages contain calories and are low in nutritional value. They may contribute to hypogly- cemia or, in the case of high-carbohydrate alcoholic beverages, hyperglycemia.

It is not advisable to increase alcohol consumption for the purpose of deriving purported health benefits.

The following dietary patterns have been shown to be effective in the prevention and management of diabetes:

Moderately low carbohydrate consumption; high consumption of plant-based protein; fats from plants

The following specific foods have been shown in some study results to be associated with a reduced risk of developing T2D:

Physical activity should be an integral component of the weight loss and diabetes care plan to optimize glucose control, decrease cardiovascular risk factors, and achieve or maintain optimal body weight.

All adults should consult their healthcare provider and/or see an exercise physiologist to discuss a safe exercise program appropriate to their abilities [1C].

To increase lean body mass, full-body resistance training should be incorporated into the activity plan 3 to 4 days per week. The training should include upper-body, core, and lower-body strengthening exercises using free

	weights, resistance machines, or resistance bands [1B].

Guidelines for healthy adults with diabetes or prediabetes:

Moderate-intensity aerobic (endurance) physical activity performed a minimum of 30 minutes 5 days per week, or vigorous-intensity aerobic physical activity performed a minimum of 20 minutes 3 days per week, should be achieved unless contraindicated. Activity can be accumulated toward the 30-minute minimum by performing bouts, each lasting 10 or more minutes [1A].

A target of 60 to 90 minutes of moderate-intensity aerobic activity per day, 6 to 7 days per week, is encouraged for weight loss if overweight or obese [1B].

Stretching exercises should be done when muscles are warm or at the end of the activity plan to loosen muscles and prevent soreness [1B].

Additional guidelines for adults with medical or physical limitations:

Incorporate balance exercises to prevent falls and injuries.

Functional Fitness Testing is useful to assess patients’ functionality and to track their progress. Testing such as 6-Minute Walk Test, 2-Minute Step Test, Balance Assessment and Hand Strength should be included at baseline and post intervention [1C].

For those with proliferative diabetic retinopathy, retinal traction, or severe nonproliferative diabetic retinopathy, activity programs that involve strenuous lifting; harsh, high-impact components; or components that place the head in an inverted position for extended periods of time may need to be revised, depending on the level of retinopathy and other retinal disease. Consultation with an eye specialist in diabetes eye care is advised.

Suggested Approximate Macronutrient Distribution According to Clinical Guideline

Recent Studies, Reviews and Meta-Analyses

Articles

Evidence-Based Diabetes Management

From the Adult Diabetes and Clinical Research sections, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts. 

CHAPTER 2. Clinical Nutrition Guideline for Overweight and Obese Adults With Type 2 Diabetes (T2D) or Prediabetes, or Those at High Risk for Developing T2D

™, we present publication of the first installment of the Joslin Clinical Guidelines, which are the principles that influence our clinical behavior every day at Joslin Diabetes Center and our affiliates and partners around the world. Although some sections of the guidelines have been in use for years, our collaboration with 

® represents our first cohesive effort to update and publish the guidelines in a searchable format, one more easily shared with audiences beyond Joslin. It is our hope that publication of the guidelines, in partnership with the leading peer-reviewed journal dedicated to research and leadership in health outcomes, will bring the Joslin Clinical Guidelines into wider use. Through use of these guidelines, patients around the world can benefit from the knowledge, research, and practices developed over more than a century of focus on the care of people with diabetes.

As explained in the overview, the Joslin Clinical Guidelines are developed by the Clinical Oversight Committee at Joslin Diabetes Center, for which we serve as chair and ex-officio members, respectively. Our Clinical Oversight Committee includes physicians, nurses, certified diabetes educators, and behavioral health specialists who are experts in treating individuals with diabetes of all ages. More importantly, our committee members are leaders in developing strategies to help those living with diabetes self-manage their disease. Our process invites the participation of faculty with special expertise who are not on the Clinical Oversight Committee; these experts serve on working groups for individual guidelines. We thank all who have participated in the development of the guidelines over many years for your contributions.

The guidelines are evidence based, and the overview explains our use of a modified form of the GRADE system (Grading of Recommendations, Assessment, Development and Evaluation). For this installment, we present the following: the Clinical Guideline for Adults With Diabetes; the Clinical Nutrition Guideline for Overweight and Obese Adults With Type 2 Diabetes (T2D) or Prediabetes, or Those at High Risk for Developing T2D; the Guideline for Detection and Management of Diabetes in Pregnancy; the Guideline for the Care of the Older Adult With Diabetes; and the Clinical Guideline for Pharmacological Management of Adults With Type 2 Diabetes. With this installment, we have covered the major issues that most physicians, registered dietitians, certified diabetes educators, nurse practitioners, physician assistants, and pharmacists will encounter in clinical practice. The Clinical Guideline for Pharmacological Management of Adults With Type 2 Diabetes has been revised to reflect recent scientific advances and regulatory developments that offer more choices than ever for diabetes management. We repeat the position that Joslin Diabetes Center announced earlier this year, when we concurred with the American Diabetes Association, the American Association of Clinical Endocrinologists, the Endocrine Society, and the American Association of Diabetes Educators that those with diabetes should aim for glycated hemoglobin of 7% or lower, not between 7% and 8%.

Is diabetes self-management challenging? Yes. But as these guidelines reflect, and as we see at the Joslin Diabetes Center every day, self-management can succeed through empowering our patients and engaging them alongside appropriate pharmacotherapy. We hope this publication serves as both a resource and an inspiration to providers who are struggling with what to do next for their patients. We invite your feedback and look forward to sharing more of the best practices developed at Joslin—so that individuals with diabetes can live the best lives possible.

Note: For a PDF of the Clinical Guidelines in this issue, download the PDF at the end of this letter. Individual PDFs of each guideline are included at the end of each chapter.

Om P. Ganda, MD, serves as chair of the Joslin Clinical Oversight Committee, and Robert A. Gabbay, MD, PhD, FACP, is senior vice president and chief medical officer of Joslin Diabetes Center.

From the Editors: Bringing the Joslin Clinical Guidelines to the Diabetes Care Community

: Clinical Guideline for Adults With Diabetes, Nutrition, Pregnancy, Older Adults, Pharmacological Management

Robert Gabbay, MD, PhD, FACP (ex officio)

Chief Medical Officer, Senior Vice President

 Clinical Guideline for Adults With Diabetes, Nutrition, Older Adults, Pharmacological Management

Senior Physician; Chair, Continuing Medical Education Committee

 Clinical Guideline for Adults With Diabetes, Pharmacological Management

Clinical Guideline for Adults With Diabetes, Nutrition, Pregnancy, Older Adults, Pharmacological Management

Nurse Leader, Nurse Practitioner at Health Care Without Walls

Associate Professor of Ophthalmology at Harvard Medical School, affiliation with Joslin Diabetes Center/Beetham Eye Institute

 Clinical Guideline for Adults With Diabetes

 Clinical Guidelines for Adults With Diabetes

Director of the Asian Clinic, assistant investigator in the section on clinical research, Co-Director of Joslin’s Asian American Diabetes Initiative

Clinical Guideline for Adults With Diabetes

Chief, Pediatric, Adolescent, and Young Adult Section

 Clinical Guideline for Adults With Diabetes, Nutrition, Pregnancy, Older Adults, Pharmacological Management

Director, Clinical and Education Programs

 Clinical Guideline for Adults With Diabetes, Nutrition

Director, Joslin Geriatric Diabetes Program

 Clinical Guideline for Adults With Diabetes, Older Adults

Clinical Guideline for Adults With Diabetes, Nutrition, Pregnancy

Staff Physician, Kidney and Hypertension Section; Director, Latino Kidney Clinic 

Director, Healthcare Services and Publications

Clinical Guideline for Adults With Diabetes, Nutrition, Pregnancy, Older Adults

Senior Physician, Director, Joslin Institute of Technology Translation

All working group members are primarily affiliated with Joslin Diabetes Center unless otherwise noted. Clinical Oversight Committee members who served on working groups are listed below members who served on working groups only.

Clinical Guidelines for Adults With Diabetes

Podiatric foot surgery, Harvard Beth Israel Deaconess Medical Center

Clinical Exercise Physiology Department Manager

Also: Ganda, Gabbay, Beaser, Cavallerano, Hafida, Hsu, Laffel, Maryniuk, Munshi, Rizzotto, Rosas, Sjostrom, Sullivan, Zrebiec

Listed below are members of the Clinical Oversight Committee and Working Groups who participated in development of the Clinical Guidelines for Joslin Diabetes Center. Faculty who participated in guideline development who are no longer at Joslin are designated with an asterisk.

Clinical Oversight Committee, Joslin Diabetes Center

The Joslin Clinical Guideline for Adults With Diabetes is designed to assist primary care physicians and specialists as they individualize the care of and set goals for nonpregnant adults with diabetes. This guideline focuses on the unique needs of the patient with diabetes. It is not intended to replace sound medical judgment or clinical decision making and may need to be adapted for certain patient care situations in which more or less stringent interventions may be necessary. This guideline was approved May 17, 2017, and updated May 25, 2018.

The needs and goals of each patient are unique. A treatment plan must be based on a thorough assessment and requires an understanding of not only the patient’s medical needs, but also other factors that may influence the treatment plan such as social history, race, cultural issues, ethnicity, education needs (including literacy and numeracy), comorbidities, and barriers to care. The patient’s diabetes management plan should include medical treatment, interventions, follow-up, and ongoing support. Use of the electronic medical record may help facilitate care, by enabling the team to track progress, ensuring goals are met, and facilitating communication flow among team members and the patient.

Diabetes is a condition that requires considerable selfmanagement. A collaborative counseling model that involves the patient in decisions and goal-setting helps promote behavioral change. Whenever appropriate, with the patient’s consent, involving family members and nonclinical caregivers in medical visits and education is valuable.

Diabetes is best managed by a team, which may include clinicians, diabetes educators (DEs), dieticians, exercise physiologists, and behavioral health specialists. The patient should be informed and fully aware of what roles the various team members play. If access to a team is not possible within the office practice, it is useful to identify community resources.

Clear communication among all providers is critical to ensure patients’ needs are being met.

While the frequency of visits for ongoing care should be individualized, monitoring the patient’s progress through medical visits is recommended at least 2 to 4 times/year. Special attention should be given to patients who do not keep scheduled appointments, have frequent hospitalizations, or miss days of work/school. Since many factors contribute to patients’ ability to manage their care, the provider should:

• Engage patients in identifying and resolving contributing factors or barriers to underutilization or overutilization of healthcare services. Patients with challenging care may benefit from consultation with endocrinologists focused on diabetes care.

• Refer to a DE, registered dietician (RD), social service professional, or behavioral health professional to address possible barriers and/or psychosocial issues

• Establish a process of follow-up communication regarding adherence to the treatment plan and sustaining behaviors

The diagnosis of diabetes mellitus can be made based upon:

• Random plasma glucose ≥200 mg/dl (11.1 mmol/L) and symptoms of diabetes (polyuria, polydipsia, ketoacidosis, or unexplained weight loss) OR

• Fasting plasma glucose* ≥126 mg/dl (6.9 mmol/L) OR

• Results of a 2-hour 75-gram oral glucose tolerance test*

• Glycated hemoglobin* (A1C) ≥6.5% (46 mmol/mol)**

*These tests should be confirmed by a repeat test, on a different day, unless unequivocally high.

**An A1C level of ≥6.5% on 2 separate days is acceptable for diagnosis of diabetes [1B]. However, some individuals may have an A1C <6.5% with diabetes diagnosed by previously established blood glucose criteria. Therefore, presence of either criterion is acceptable for diagnosis. Those with an A1C of 5.7%-6.4% (39-46 mmol/mol) are considered to have prediabetes, and they are at high risk for developing diabetes. These patients should be treated with lifestyle changes and followed more frequently.

 The A1C test should be performed in a laboratory using a method that is certified by the National Glycohemoglobin Standardization Program and standardized to the Diabetes Control and Complications Trial assay.

A point-of-care (POC) A1C is not acceptable for diagnosis of diabetes.

See above section on Diagnosis of Diabetes Mellitus.

The A1C target goal should be individualized for each patient. A goal of <7.0% (53 mmol/mol) is chosen as a practical level for most patients to reduce the risk of long-term complications of diabetes. Achieving this goal is recommended if it can be done safely and practically [1B].

Alternative A1C goals may be set, based upon presence or absence of microvascular and/or cardiovascular complications, hypoglycemic unawareness, cognitive status, and life expectancy [1A]. For patients with longstanding type 2 diabetes (T2D) with preexisting cardiovascular disease (CVD), or high coronary artery disease (CAD) risk (diabetes plus 2

or more additional risk factors), consider revising A1C goals to avoid adverse consequences of tight glycemic control, eg hypoglycemia [1A].

Some clinicians may translate patients’ A1C level into their estimated average glucose level, based upon the work of the A1C Derived Average Glucose Study. This metric is also a valid tool that may be used to assess the response of patients to their diabetes treatment plan [1C].

Joslin’s A1C target goal for most patients is consistent with that of the American Diabetes Association (ADA). Other expert panels, such as the American Association of Clinical Endocrinologists, suggest that the A1C target goal should be <6.5% in those newly diagnosed with diabetes and without comorbidities. Recent recommendation of 7% to 8% for most individuals with T2D by the Ameican College of Physicians are not endorsed by us ( see caveats above).

The A1C may not reflect glycemic control in special patient populations, including pediatric and geriatric populations, patients with anemia or other blood disorders resulting in rapid turnover of red blood cells, in chronic liver and renal disease, following recent blood transfusions, or while patients are hospitalized. It is therefore important to interpret

A1C results accordingly when determining treatment plans and goals.

Monitor the A1C 2-4 times a year as part of the scheduled medical visit [1C] to evaluate efficacy of the treatment plan. The A1C may be checked more frequently if the treatment program requires revision, or the advice regarding behavior changes needs reinforcement. Having the A1C result at the time of the visit can be useful in making timely treatment decisions [1C].

Alternatively, the A1C may be performed prior to the medical visit POC method.

If A1C is ≥7% and <8%, or above the individualized goal, for 6 or more months:

• Review and clarify the management plan with the patient with special attention given to address:

-- self-monitoring blood glucose (SMBG) schedule and technique

-- treatment of hypoglycemia and hyperglycemia

• Reassess goals and adjust medication as needed [1A]

• Establish and reinforce individualized glycemic goals with patient

• Refer patient to a certified diabetes educator (CDE) for evaluation, diabetes self-management education (DSME), and support for ongoing consultation [1C] 

• Consider referral to RD for medical nutrition therapy (MNT) [1B]

• Schedule follow-up appointment within 3-4 months or more frequently as the situation may dictate

• Review and clarify the plan as previously noted

• Assess for psychosocial stress as a potential barrier to adequate response to treatment [1C]

• Establish and reinforce individualized glycemic goals with the patient

• Refer patient to DE for evaluation, DSME, and support for ongoing consultation. Document reason if no referral initiated

If the patient has a history of severe recurrent hypoglycemia or hypoglycemia unawareness (a condition in which the patient is unable to recognize symptoms

• Assess for changes in daily routine such as reduced food intake or increased physical activity [1C]

• Refer to DE for evaluation, DSME, and hypoglycemia prevention; encourage family/friend attendance

• Discuss and reinforce goals with patient

• Adjust medications to minimize hypoglycemia risk [1B]

• If insulin-treated, consider use of a more physiologic insulin replacement program, such as basal/bolus therapy

• Consider and screen for other medical causes

• Consider referral for blood glucose awareness training, if available

• Consider use of continuous glucose monitoring [2B]

From the Adult Diabetes and Clinical Research sections, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts.

CHAPTER 1. Clinical Guideline for Adults With Diabetes

The Joslin Guideline for Detection and Management of Diabetes in Pregnancy is designed to assist internal medicine specialists, endocrinologists, and obstetricians in individualizing the care of and setting goals for women with preexisting diabetes who are pregnant or planning pregnancy. It is also a guide for managing women who are at risk for or who develop gestational diabetes mellitus (GDM). This guideline is not intended to replace sound medical judgment or clinical decision making. Clinical judgment determines the need for adaptation in all patient care situations; more or less stringent interventions may be necessary.

3.1.0 SCREENING FOR GESTATIONAL DIABETES MELLITUS

3.2.0 PRECONCEPTION CARE. For preexisting type 1 diabetes (T1D) or type 2 diabetes (T2D)

The objective of the Joslin Guideline for Detection and Management of Diabetes in Pregnancy is to support clinical practice and to influence clinical behaviors in order to improve clinical outcomes and assure that patient expecta- tions are reasonable and informed. This guideline was approved November 13, 2016, and updated February 12, 2018.

See at end of Chapter 3 (download PDF at end of chapter).

Fasting and pre-meal glucose: plasma 80 to 110 mg/dL [1C]

1-hour postprandial blood glucose: plasma 100 to 155 mg/dL [1C]

Glycated hemoglobin (A1C): <7% and as close to 6% as possible, without severe hypoglycemia [1B]

Educate women of childbearing age about the importance of near-normal blood glucose control prior to conception.

Refer to a specialist in maternal—fetal medicine and/ or endocrinology/diabetes for counseling, assessment of maternal and fetal risk, and guidance in achieving management goals. This includes all women who are planning pregnancy and women who are not planning pregnancy but are using inadequate contraception and have A1C greater than 7%.

Assess diabetes self-management, including meal planning, insulin care and use, activity program, medication schedule, self-monitoring of blood glucose (SMBG), treatment for hypoglycemia and hyperglycemia, and sick day management, utilizing diabetes educators (DEs) as appropriate. Review maternal and fetal health issues.

Begin a multivitamin with 400 mcg of folic acid to supplement average daily intake of 400 mcg for a total daily intake of 800 mcg to 1 mg of folic acid to decrease the risk of neural tube defects. Patients with a prior pregnancy affected with a neural tube defect should take folic acid 4 mg daily.

Strongly advise smoking and alcohol cessation.

Refer overweight and obese women with and without known diabetes or polycystic ovary syndrome (PCOS) for medical nutrition therapy with a goal of 5% to 10% weight loss based on 2009 Institute of Medicine recommendation

Take thorough medical and obstetrical history, including comprehensive review of diabetes history and management.

Eye evaluation: dilated comprehensive eye exam and pregnancy clearance by an ophthalmologist; should also include a discussion about the risk of developing and/or the progression of diabetic retinopathy during pregnancy.

Kidney function assessment: random urine albumin/ creatinine ratio and serum creatinine. Refer to nephrology if urine protein >1 gram.

Thyroid evaluation: Check thyroid stimulating hormone level.

Gynecology evaluation: Make sure pelvic exam and Pap smear are up to date.

Cardiac evaluation: If asymptomatic and ≥ 35 years of age with 1 or more additional risk factors (hypertension, smoking, family history of coronary artery disease, hypercholesterolemia, albuminuria, or nephropathy), recommend 1 or more of the following: electrocardio- gram (ECG), echocardiogram, or exercise tolerance test (ETT). If symptomatic, recommend ECG and echocar- diogram or ETT and consider referral to cardiologist.

Check vitamin B12 level in patients consuming more than 1 mg folic acid daily, as high-dose folic acid may mask a B12 deficiency.

Discontinue oral antihyperglycemic therapy; start insulin. An exception is metformin, which may be continued during anovulatory infertility and in the first trimester in patients with PCOS or T2D. Prior

	to the first prenatal visit, the patient should begin increasing doses of insulin as necessary to control blood glucose while metformin is tapered off or discontinued. Metformin should not be used beyond the first trimester or in lieu of insulin based on safety and efficacy data available at this time. 	

Metformin crosses the placenta and achieves therapeutic levels in the fetus. Presently, there are no long term randomized controlled trials (RCT) regarding outcomes in offspring of mothers with preexisting diabetes treated with metformin during pregnancy. (See 3.3.3b regarding outcomes in infants exposed to metformin in utero in PCOS and GDM.).

Other oral medications have not been adequately studied for the treatment of preexisting T2D in pregnancy.

The rapid-acting insulin analogs lispro and aspart lower postprandial blood glucose and decrease the risk of nocturnal hypoglycemia. Patients on lispro and aspart prior to conception may continue them during pregnancy. Patients on regular insulin may be switched to lispro or aspart if 1-hour postprandial blood glucose levels are above target and/or the patient is also experiencing pre-meal or nocturnal hypoglycemia.

No information exists on the safety of using the insulin analogs glulisine and degludec in pregnancy. We cannot recommend their use at this time.

A rapid-acting insulin, lispro or aspart, may be delivered either through multiple daily injections or an insulin pump.

From the Adult Diabetes and Clinical Research sections, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts

June 2018

CHAPTER 2. Clinical Nutrition Guideline for Overweight and Obese Adults With Type 2 Diabetes (T2D) or Prediabetes, or Those at High Risk for Developing T2D

From the Editors: Bringing the Joslin Clinical Guidelines to the Diabetes Care Community

Clinical Oversight Committee, Joslin Diabetes Center

CHAPTER 1. Clinical Guideline for Adults With Diabetes

CHAPTER 3. Guideline for Detection and Management of Diabetes in Pregnancy

CHAPTER 4. Guideline for the Care of the Older Adult With Diabetes

CHAPTER 5. Clinical Guideline for Pharmacological Management of Adults With Type 2 Diabetes