Physiological and Lifestyle Traits of Metabolic Dysfunction in the Absence of Obesity

AbstractPurpose of ReviewIndividuals with metabolically unhealthy normal weight (MUNW) have an adverse cardiometabolic risk factor profile in the absence of excess body weight, and increased risk for diabetes and heart disease. We critically review some physiological traits and lifestyle characteristics of the MUNW phenotype.Recent FindingsThe prevalence of MUNW varies considerably around the world and among ethnicities, partly because of different definitions; on average, this phenotype affects about ~  30% of normal weight persons globally. Most studies have recruited MUNW subjects who, although within the normal weight range, are significantly “more obese” than their metabolically healthy lean peers (greater body mass index or total body fat); hence one cannot ascertain whether observed di fferences are true traits of the MUNW phenotype of simply secondary to greater relative adiposity within the normal range. Carefully matched studies have indicated that MUNW can exist in the absence of excess total body fat. These subjects have a preferential accumulation of fat in the upper body (a bdominal subcutaneous and visceral adipose tissues) and the liver, but not skeletal muscle; perhaps surprisingly, this predominantly “android” fat distribution does not translate into increased waist circumference. The MUNW phenotype is associated with lower aerobic fitness and muscle mass and s trength, but whether this is simply due to inadequate regular physical activity is not e...

Source: Current Diabetes Reports - March 30, 2020 Category: Endocrinology Source Type: research