Profile of Bone Mass and Its Determining Factors in Type 2 Diabetes: Case-Control Study

Abstract

Background: Type 2 diabetes mellitus, beyond its well-known cardiovascular and neurological complications, is now increasingly recognized as having deleterious effects on bone tissue. It’s thus presented as an independent risk factor for bone fragility with a considerable fracture risk relating to many more or less intricate parameters. The general objective of our study is to assess bone mass during type 2 diabetes in Senegalese women. Methodology: We had carried out a cross-sectional and descriptive study. Socio-demographic characteristics were collected on the basis of a questionnaire. Then each of the subjects had undergone a complete clinical examination followed by a blood sample for a biological assessment of certain cardiovascular risk factors. Bone mass was measured using a bio-impedancemeter. Results: We recruited 88 women with type 2 diabetes and 83 healthy control women. The mean age of diabetic subjects was 52.7 years ± 6.8 (with extremes of 39 and 74 years). In control, the mean age was 51.0 ± 8.5 years (with extremes of 35 and 72 years). Among the diabetic subjects, 22 subjects or 25% practiced a regular walk against 27 (32.5%) in the control. Forty-three among the diabetic subjects (48.8%) were known hypertensive and followed. According to the body mass index, 71 patients (80.7%) were overweight compared to 59 (71.1%) controls. According to the waist size, 80 (90.9%) diabetic subjects had an elevated waist size compared to 69 control women (83.1%). Among diabetic subjects, 41 patients (46.5%) were hyperglycemic imbalance according to fasting blood glucose and 59 patients (67%) according to glycated hemoglobin level. Thirty-seven diabetics (42%), had both high fasting blood glucose and elevated glycated hemoglobin. The mean duration of diabetes was 8.68 ± 7.18 years. We found significantly higher bone mass in type 2 diabetic subjects (p = 0.03). Among diabetics, 27.3% had low bone mass compared to 36.1% of control. It’s noted that the subjects of the “low bone mass” group among the control subjects also have a significant drop in other anthropometric parameters (weight, body mass index, waist size, muscle mass). It should also be noted that the fat mass is significantly higher in diabetic subjects with normal or even high bone mass. In control subjects, bone mass was positively correlated with weight (r = 0.36; p = 0.001), muscle mass (r = 0.93; p < 0.0001) and fasting blood glucose (r = 0.26; p = 0.02); and negatively correlate with age (r = 0.22; p = 0.04). On the other hand, in type 2 diabetic subjects, bone mass is positively correlated with age (r = 0.22; p = 0.04), muscle mass (r = 0.89; p < 0.0001) and the diabetes duration (r = 0.44; p = 0.001). Conclusion: Bone mass is higher in type 2 diabetics compared to healthy controls. Chronic hyperglycemia and the diabetes duration are believed to be responsible for the increase in bone mass. In addition, an increase in muscle mass would lead to an increase in bone mass.