Bone loss and bone turnover in diabetes

Area of Science:

• Endocrinology
• Bone Metabolism
• Diabetes Research

Background:

• Conflicting reports exist regarding diabetes' effect on bone density.
• Previous studies have not fully elucidated the long-term bone density changes in diabetic patients.

Purpose of the Study:

• To investigate the longitudinal changes in bone density in patients with type I and type II diabetes.
• To compare bone density and bone formation rates between diabetic patients and non-diabetic controls.

Main Methods:

• Longitudinal study of 109 patients (46 type I, 63 type II diabetes) with initial measurements in 1978 and follow-ups.
• Bone density measurements (radial) and bone biopsies for histological assessment of bone formation were performed.
• Patients were restudied approximately 2.5 and 12.5 years after baseline.

Main Results:

• Initially, diabetic patients had significantly lower radial bone density than controls.
• Bone formation rates were markedly depressed in osteopenic diabetic patients.
• Type I diabetes showed continued bone loss, maintaining the initial deficit.
• Type II diabetes patients exhibited slower bone loss, completely correcting the initial deficit over time.
• Several type II diabetes patients showed improved bone mineral density z-scores, even exceeding normal ranges.

Conclusions:

• Diabetes influences bone density through multiple mechanisms including impaired bone formation and altered resorption.
• Type I diabetes is associated with persistent bone loss, while type II diabetes may lead to improved bone density over the long term.
• Low bone turnover in diabetes may retard age-related bone loss, with potential for bone density normalization or increase in type II diabetes.