Age-related changes in abdominal fat distribution in Japanese adults in the general population.

Objective: Early studies have indicated that body fat shifts from peripheral stores to central stores with aging. The objective of this study was to investigate age-related changes in abdominal fat distribution of Japanese men and women of the general population over a wide range of body mass indices (BMI).

Methods: A total of 2,220 non-diabetic, apparently healthy Japanese adults (1,240 men and 980 women; age range 40-69 years) were included in the study sample. All subjects underwent a CT scan at the level of the umbilicus, and the areas of visceral adipose tissue (AT) and subcutaneous AT were quantified.

Results: When the subjects were stratified by BMI into 18.5-23.0 kg/m(2), 23.0-27.5 kg/m(2), and 27.5 kg/m(2) or higher, visceral AT was positively correlated with age in all of the BMI strata in both genders (p<0.01). In contrast, subcutaneous AT was negatively correlated with age in men with BMIs in excess of 23.0 kg/m(2) (p<0.01) and not at all in women. The mean levels of subcutaneous AT were over 2-fold greater than visceral AT in women aged 60-69 years in any BMI stratum.

Conclusion: In Japanese men and women, visceral AT was increased with age in all BMI strata in both genders, whereas subcutaneous AT was decreased with age in men with BMIs in excess of 23.0 kg/m(2) and not at all in women. Even with these age-related changes in abdominal fat distribution, women retained the subcutaneous-dominant type of fat distribution up to 70 years.