Body fat distribution and inflammation among obese older adults with and without metabolic syndrome

Abstract

The protective mechanisms by which some obese individuals escape the detrimental metabolic consequences of obesity are not understood. This study examined differences in body fat distribution and adipocytokines in obese older persons with and without metabolic syndrome. Additionally, we examined whether adipocytokines mediate the association between body fat distribution and metabolic syndrome. Data were from 729 obese men and women (BMI ≥ 30 kg/m(2)), aged 70-79 participating in the Health, Aging and Body Composition (Health ABC) study. Thirty-one percent of these obese men and women did not have metabolic syndrome. Obese persons with metabolic syndrome had significantly more abdominal visceral fat (men: P = 0.04; women: P < 0.01) and less thigh subcutaneous fat (men: P = 0.09; women: P < 0.01) than those without metabolic syndrome. Additionally, those with metabolic syndrome had significantly higher levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and plasminogen activator inhibitor-1 (PAI-1) than individuals without metabolic syndrome. Per standard deviation higher in visceral fat, the likelihood of metabolic syndrome significantly increased in women (odds ratio (OR): 2.16, 95% confidence interval (CI): 1.59-2.94). In contrast, the likelihood of metabolic syndrome decreased in both men (OR: 0.56, 95% CI: 0.39-0.80) and women (OR: 0.49, 95% CI: 0.34-0.69) with each standard deviation higher in thigh subcutaneous fat. These associations were partly mediated by adipocytokines; the association between thigh subcutaneous fat and metabolic syndrome was no longer significant in men. In summary, metabolically healthy obese older persons had a more favorable fat distribution, characterized by lower visceral fat and greater thigh subcutaneous fat and a more favorable inflammatory profile compared to their metabolically unhealthy obese counterparts.

Figure 1

Box plots ^a of visceral and thigh subcutaneous fat according in obese men and women with and without metabolic syndrome ^a Dark line in the middle of the box is the median; bottom and top of the box represent the 25^th and 75^th percentile; end of the whiskers represent the minimum and maximum

Figure 2

Adjusted mean values of visceral and thigh subcutaneous fat according the number of metabolic abnormalities ^{a a}Adjusted for age, race, site, education, physical activity, smoking, alcohol intake, and total fat

Figure 3

Odds ratios and 95% confidence intervals of metabolic syndrome according to visceral fat and thigh subcutaneous fat ^{a a}Model includes both visceral and thigh subcutaneous fat and adjusted for age, race, site, education, physical activity, smoking, alcohol intake, and height