TYPE 2 DIABETES MELLITUS AND THE EFFECTS OF LIFESTYLE ON BONE MINERAL DENSITY IN PRE-AND POSTMENOPAUSAL WOMEN.

Abstract

Background: There have been conflicting reports about the effect of diabetes and the lifestyle of diabetic patients on bone mineral density (BMD). The aim of this study is to investigate the relation between effects of life style in type 2 diabetic patients and BMD at lumbar spine and proximal of femur in pre and postmenopausal women.

Methods: In a historical cohort study 20 type 2 Diabetics and 57 non-diabetics pre-menopausal and 126 type 2 Diabetics and 315 non-diabetics postmenopausal, were recruited from women referred to bone densitometry unit of Endocrinology and Metabolism Research Center of Tehran University of Medical Sciences. BMD measurements were also made to the spine and proximal femur (Neck, Wards, and Shaft) by dual energy X-ray absorptiometry technique. Exclusion criteria were endocrine, rheumatologic or chronic diseases in both groups. Type 2 diabetic cases and non-diabetics were matched for age and body mass index (BMI) for each pre- and postmenopausal group.

Results: A total of 146 type 2 Diabetic patients without other endocrine disorders and 372 non-diabetic women, aged 40-81 years were enrolled. Among the pre-menopausal women there were no significant differences in BMD of spine and femur in type 2 Diabetic and non-diabetic women. Postmenopausal type 2 Diabetic patients had higher BMD at the lumbar spine than non-diabetic women.

There was an age-related decrease in BMD (lumbar and femur) in all groups and a significant correlation between BMI and BMD was observed. After adjusting for age and BMI, we investigated the effect of lifestyle on BMD at all sites. Occupation was positively associated with BMD in postmenopausals, but not in premenopausal women. Among the dietary variables considered, milk, yogurt and cheese were all associated with increases in BMD in at least one site in type 2 Diabetic patients. Smoking was not associated with BMD; this result may be due to the fact that the exposure was far smaller in women (only 7.8% of Type 2 Diabetics had ever smoked).

Conclusion: Bone loss and osteoporosis cannot be considered a complication of type 2 Diabetes mellitus. Physical activity and milk consumption in postmenopausal type 2 Diabetic women might act as a protective factor against bone loss.