Obesity has been linked to numerous medical concerns, such as a decline in life expectancy due to its connection with metabolic and cardiovascular disorders, and has long been touted as an increasing worldwide public health epidemic. However, the complex relationship between weight and cardiovascular risk is still largely under investigation.
A recent study, published in The Journal of Clinical Endocrinology and Metabolism, sought to dive further into the impact of body size phenotypes on cardiovascular risk and effectively evaluate the prevalence of subclinical atherosclerosis across phenotypes.
The researchers enrolled nearly 4000 asymptomatic participants with no known cardiovascular disease between the ages of 40 and 54. The investigators aimed to determine the following: the prevalence of each of the 6 body size phenotypes (normal weight, overweight, and obese, each with or without cardiometabolic abnormalities); body mass index (BMI) and cardiometabolic status separately; the presence and extent of subclinical atherosclerosis by body type phenotypes; and finally, the distribution of traditional risk factors, lifestyle factors, and psychosocial characteristics across body size phenotypes.
Based on their BMI, individuals were classified as being normal weight (BMI < 25.0 kg/m2), overweight (BMI 25.0-29.9 kg/m2), or obese (BMI > 30.0 kg/m2). Cardiometabolic body size phenotypes were determined by the presence of at least 1 of the 6 cardiometabolic abnormalities (blood pressure, fasting blood glucose, triglycerides, low high-density lipoprotein cholesterol, homeostasis model assessment-insulin resistance index, and high-sensitivity C-reactive protein), as well as BMI. The occurrence of 1 or more of the 6 cardiometabolic components was defined as “metabolically unhealthy,” while the absence of all was defined as “metabolically healthy.”
The primary outcomes were measured by use of a 2-dimensional vascular ultrasound (2DVUS) and non-contrast cardiac computed tomography (CCT). These measures were then combined to determine the range of subclinical atherosclerosis.
The study showed that men (n = 2435) were more often metabolically unhealthy when compared with women (65.3% vs 42.0%; P < .001), and had lesser incidence of normal weight (26.0% vs. 68.3%; P < .001). In metabolically healthy participants, the authors found that the incidence of subclinical atherosclerosis increased as BMI increased (49.6% for normal weight, 58.0% for overweight, and 67.7% for obese). However, in metabolically unhealthy patients, fewer differences were noted across BMI categories (61.1%, 69.7%, and 70.5% for normal weight, overweight, and obese, respectively).
The authors noted that when BMI and cardiometabolic abnormalities were assessed separately, the correlation between body size phenotypes with the prevalence of subclinical atherosclerosis was mostly driven by the coexistence of cardiometabolic risk factors: adjusted overall response (OR) = 1.04 (95% CI, 0.90-1.19) for overweight and OR = 1.07 (95% CI, 0.88-1.30) for obese.
Overall, the occurrence of subclinical atherosclerosis was found to vary across body size phenotypes. In terms of interventions, pharmacologic and lifestyle changes may modify cardiovascular risk by enabling the transition from one phenotype to the other. However, the authors concluded that further longitudinal studies are needed to evaluate the impact of lifestyle and treatment on the delay or acceleration of subclinical atherosclerosis.
Rossello X, Fuster V, Olivia B, et al. Association between body size phenotypes and subclinical atherosclerosis. J Clin Endocrinol Metab. 2020;105(12). doi:10.1210/clinem/dgaa620