Insulin is inversely associated with bone mass, especially in the insulin-resistant population: the Korea and US National Health and Nutrition Examination Surveys.

Abstract

BACKGROUND: Insulin is an important osteotropic hormone but may be negatively

associated with bone mass after adjustment for body mass index in adolescent

populations. However, the association between insulin and bone mass in adults

remains unclear. OBJECTIVE: The objective of the study was to investigate whether

insulin was associated with bone mass in adults and, if so, whether the

association was positive or negative. DESIGN: This study had a cross-sectional

design, using data from the Fourth Korea National Health and Nutrition

Examination Survey (KNHANES) 2008-2009 and the US National Health and Nutrition

Examination Survey (NHANES) 1999-2006. SETTING: The setting for the study was the

Korean and US population. PARTICIPANTS: A total of 7271 KNHANES and 3399 NHANES

participants were included. MAIN OUTCOME MEASURES: Anthropometric parameters and

bone mass data, fasting glucose and insulin, height, weight, and markers related

to insulin resistance were measured. RESULTS: After adjusting for confounding

factors, there was an inverse relationship between insulin and total body bone

mineral content in the KNHANES and NHANES subjects. In a stratified analysis, an

association between insulin and bone mass was apparent, especially in the highest

homeostatic model of assessment of insulin resistance quartile in the Korean

subjects. However, this association was seen only in men in the US subjects.

CONCLUSIONS: There is an inverse relationship between insulin and total body bone

mineral content after adjustment for confounding factors in Korean and US

subjects, especially in the insulin-resistant population. This strongly suggests

that the adverse influence of insulin on bone mass likely reflects the effects of

other factors associated with insulin resistance rather than being a direct

action of insulin itself.