Sclerostin levels linked to bone quality in diabetes patients
MedWire News: Circulating sclerostin levels are increased in individuals with Type 2 diabetes and may play a role in impairing bone metabolism and quality in this population, report Spanish researchers.
Sclerostin levels are also related to the duration of diabetes and glycated hemoglobin (HbA1c) levels, they say.
Manuel Muñoz-Torres (Hospital Universitario San Cecilio, Granada) and team explain that sclerostin, a major regulator of the Wnt signaling pathway, is present almost exclusively in osteocytes.
"Activation of the Wnt signaling pathway results in expansion of osteoprogenitor cells as well as reduced apoptosis, leading to anabolic effects on bone," they add.
As reported in the Journal of Clinical Endocrinology and Metabolism, the researchers compared serum sclerostin levels in 74 diabetes patients with those in 50 age-matched, diabetes-free individuals.
They analyzed the relationship between sclerostin and calciotropic hormones, bone turnover markers, bone mineral density (BMD), and morphometric vertebral fractures.
The authors found that sclerostin levels were significantly higher in Type 2 diabetes patients than in healthy individuals (54.6 vs 42.1 pmol/L).
Sclerostin levels were negatively correlated with bone turnover markers, and positively correlated with duration of diabetes, HbA1c, and BMD in the diabetes patients.
The researchers also found that diabetes patients with osteoporosis had significantly lower sclerostin concentrations than those without osteoporosis (44.0 vs 56.1 pmol/L).
In addition, parathyroid hormone (PTH), which has an inhibitory role in sclerostin production, was found at lower concentrations in Type 2 diabetes patients than in those without the condition, and was negatively associated with sclerostin levels in the total sample.
"These findings are consistent with phosphocalcic balance alterations described in Type 2 diabetes and could explain in part the increase in sclerostin that we observed in diabetes," write Muñoz-Torres et al.
They say their results suggest that the Wnt signaling pathway is impaired in Type 2 diabetes, leading to deterioration of osteoblastogenesis and increased bone fragility.
"Additional studies are needed to evaluate the role of sclerostin in bone metabolism in this population," concludes the team.
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By Sally Robertson