Use of metformin to treat patients with type 2 diabetes shows no association with bone fractures.
Long-term insulin use also showed no association with fractures, whereas current treatment with insulin was associated with an increase in the risk of fractures in men but not in women, reported Dr. Matteo Monami of the University of Florence (Italy), and colleagues. They conducted a case-control study in a cohort of 1,945 diabetic outpatients. They compared 83 patients who had bone fractures with a control group of 249 patients matched for age, sex, duration of diabetes, body mass index, hemoglobin A1c, comorbidity, smoking, and alcohol abuse. The average patient age was 69 years, 64% of patients in each group were female, and in both groups, patients had had diabetes for a mean 12.5 years.
In those with fractures, 29% had been exposed to secretagogues for at least 36 months in the previous 10 years, compared with 41% of controls, a significant difference. After adjusting for concomitant hypo-glycemic medications, there was no significant link between bone fractures and long-term use of any of the medications, including secretagogues, metformin, and insulin.
However, fractures were significantly more likely in men who were undergoing insulin treatment than in those who were not, with an adjusted odds ratio of 3.2. There was no similar significant association in women (Diabetes Care 2008;31:199–203).
“The results are consistent with the hypothesis that insulin could increase [fracture] risk through falls due to hypoglycemic episodes without negative effects on bone metabolism,” said the authors, who made no disclosures about conflicts of interest.