Lean body mass is not beneficial, but may be detrimental for glucose tolerance - Splitting body mass index according to body composition.

ABSTRACT

AIMS: To study the combined effect of lean mass index (LMI) and fat mass index (FMI) on glucose regulation based upon findings in an oral glucose tolerance test (OGTT) and homeostasis model assessment of insulin resistance (HOMA-IR). METHODS: We conducted a population-based, cross-sectional study including 1617 participants without diabetes born in Helsinki from 1934 through 1944. LMI and FMI were calculated as lean and fat mass (kg)/height (m2). For analysis of the association between interaction of LMI and FMI and glucose regulation the participants were divided into tertiles of FMI and LMI. RESULTS: In men LMI correlated positively with (fasting plasma glucose) FPG and HOMA-IR in the middle and high FMI level with a significant interaction between FMI and LMI on HOMA-IR. In women LMI was not associated with glucose regulation. In both men and women increased FMI was associated with increased FPG and 2-h plasma glucose concentrations and HOMA-IR. CONCLUSIONS: In men high lean mass accompanied with fatness may be detrimental for glucose tolerance, whereas in women lean mass seemed to have little effect on glucose regulation. Fatness is the major determinant of glucose intolerance.