Body composition in normal subjects: relation to lipid and glucose variables

Abstract

Objective: To describe sex- and age-dependent values of total and regional body composition as determined by dual-energy X-ray absorptiometry (DXA) in normal subjects, and furthermore to relate body composition measurements to blood lipids, glucose and insulin concentrations.

Design: A cross-sectional study.

Subjects: 173 (84 male and 89 female) healthy subjects, BMI < 30 kg/m2.

Measurements: Body composition parameters including data on total bone mineral content (TBMC), total bone mineral density (TBMD), lean body soft tissue mass (LTM), total and regional fat mass (FM) were estimated in all subjects. In 87 of the subjects fasting blood glucose, S-insulin and lipid profile were measured.

Results: The study population was for each sex divided into five decades for which results on body composition and blood lipids are presented. Body weight increased 2 kg per age decade, representing a significant increase in both total FM and relative FM (FM%BW) with age, and in males a central accumulation of FM. LTM decreased significantly in males but not in females, whereas TBMC and TBMD remained constant in males, but decreased in females. A significant correlation between relative FM and S-cholesterol, S-triglyceride, and in males S-insulin was found.

Conclusion: The present study gives coherent data on bone mineral content, lean body soft tissue mass total and regional fat mass for 173 healthy subjects with a BMI below 30 kg/m2. Total body fat mass increases, and lean mass decreases with age. In males a simultaneous central accumulation of fat mass is observed. The well-known relationship between central obesity and lipids is confirmed even in non-obese subjects.