Leptin predicts bone mineral density in men with Type 2 diabetes
MedWire News: Increased levels of leptin are associated with raised bone mineral density (BMD) in men with Type 2 diabetes, report researchers.
Leptin is thought to stimulate bone formation and inhibit osteoclastogenesis, thus having an overall positive effect on BMD, but the exact mechanism for this is unknown.
As patients with diabetes are commonly leptin-resistant and thought to be at increased risk for fractures, Noboru Takamura (University of Nagasaki, Japan) and colleagues investigated links between leptin concentration and BMD in 168 Belarusian men with Type 2 diabetes aged 45-65 years.
The participants had a mean leptin level of 7.8 g/l, ranging from 3.4-16.1 g/l. BMD of the femur was measured using X-ray absorptiometry.
After adjusting for possible confounding factors, such as body mass index, waist-to-hip ratio, insulin resistance, and triglycerides, the researchers found that BMD significantly and positively correlated with (log) leptin levels.
Takamura and co-workers suggest that leptin may stimulate bone formation by "acting on human marrow stromal cells to enhance osteoblasts and inhibit adipocyte differentiation," and may inhibit osteoclastogenesis by "decreasing the receptor activator of nuclear factor-jB and its ligand and increasing the production of osteoprotegerin, a mediator of mineral metabolism."
The researchers concede that the study size was small and that they did not measure specific body composition values such as waist-to-thigh ratio or fat mass.
However, they say that "BMD of the femur was positively associated with leptin in male patients with Type 2 diabetes mellitus."
Takamura et al conclude in the journal Acta Diabetologia: "Further research is necessary to confirm this association and to develop ways to correct abnormalities of bone metabolism in patients with Type 2 diabetes mellitus."
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By Helen Albert