Diabetes Cure Story
TYPE 2 DIABETES MELLITUS (DM) and its effects on falls, bone mass, bone turnover and fractures have been the focus of numerous scientific reports. Although small and early studies reported either unchanged or decreased bone mineral density (BMD) in diabetics, all large epidemiological studies now point unanimously to an increase in bone mass. In seven recent trials including from 70–792 diabetics, the mean increase in BMD was approximately 7.0% (range, 3.7–10.7%) at the lumbar spine and 6.2% (4.0–12.1%) at the hip. This comparatively large increase in BMD persisted even after correction for body weight or body composition. Numerous other causes have been proposed to partly account for that difference, i.e. hyperinsulinemia, poor glycemic control, effects on parathyroid function, bone turnover, or greater androgenicity. Most studies that aimed to delineate pathophysiologic mechanisms were, however, carried out on small samples or ill-defined populations, often including patients with type 1 DM. The circumstances whereby hyperglycemia affects bone mass remain largely unclear.
It is well known that diabetics show an increased propensity to fall due to visual impairment and neuropathy, as well as foot problems and presumably accelerated cognitive decline. Such diabetes-associated complications tend to become clinically more significant over the years and may increase the risk for falls and fractures. At the same time, potential fracture preventive effects of DM on bone turnover and bone mass may overlap with a time period in which diabetes-related morbidity increases. Looking at diverse populations of diabetics at different ages may thus generate conflicting results because the time dependency of negative as well as positive effects on fracture risk may develop differently over the years. One would need large longitudinal studies of well-defined patient populations to control for these confounders.
Because on the one hand, according to the National Center for Health Statistics, the prevalence of DM in nursing homes is estimated to be around 17%, and on the other, the effects on bone mass are quite substantial in the cohorts reported to date, we intended to look for any diabetes-related effects on bone metabolism and fracture rate in institutionalized individuals. Here, the scope of the problem is especially large because 3–5% of these patients develop a hip fracture annually. These fractures are triggered by physical and cognitive handicaps, malnutrition, vitamin D deficiency, and increased bone turnover, by numerous comorbidities in most cases, and finally by high intake of the most various medications. Because it would be too strenuous for most of these patients to participate in a study demanding transportation and an extended hospital stay, we chose to visit nursing home patients with study teams equipped with ultrasound devices for measuring bone density and equipment for obtaining high-quality blood specimens
