Improving A1c may help bone health in type 1 diabetes

By, Lisa Foster-McNulty

Some encouraging research was presented at the European Congress of Endocrinology meeting in May of this year.  It showed that improving the A1c seems to ease loss of bone mineral density (BMD)and bone turnover in people with type 1 diabetes. 

Eleftheria Barmpa and colleagues from the Department of  Endocrinology and Metabolic Disease at the University of Thessaly in Greece studied 107 patients with type 1 diabetes.  The average age was 34 years, 48 were men, and on average the participants had diabetes for 15 years.  The average BMI was 23 and A1c was 8.2%.  They were compared to 95 healthy controls who were matched for age, sex, and BMI.  The participants had DXA scans of the lumbar spine and neck of the femur to evaluate bone health.  A1c, bone resorption as evaluated by something called beta-CTx, and bone formation , which was assessed by blood levels of tP1NP (total procollagen type 1 N-terminal propeptide), were measured in both groups.  In the diabetes group, 50 patients had the same measurements repeated again at one year. 

The initial average BMD was lower for the patients in the diabetes group compared to control subjects at the lumbar spine and the neck of the femur.  The diabetes patients had lower T-scores at both sites.  T-scores are how many units, called standard deviations, that bone density is above or below the average.  Between the groups, there were no differences in beta-CTx or tP1NP.

At one year, 36 of the 50 diabetes patients had a reduction in A1c of at least 0.5%.  Eight held level with their initial A1c, and six patients experienced an increase in A1c of at least 0.5%.  In the group of 36 patients with an improved A1c, researchers noted an average increase of 3.3% in bone mineral density  at the lumbar spine, and an increase of 5.6% at the femoral neck.  They also noted a higher tP1NP than at baseline.

The researchers concluded that improving blood glucose control seems to improve BMD and bone turnover.  This could be a way to stabilize bone mass in people with type 1 diabetes.  We all want more years of good health, so it’s helpful to identify strategies that can have a positive impact on bone health in this population.  This finding is just one more reason to work towards improved control of glucose levels.