Type 2 Diabetes Mellitus and Osteoporosis: Site-Specific Bone Mineral Density Variations and Metabolic Correlations in Postmenopausal Saudi Women

<i>Background and Objectives:</i> Osteoporosis (OP) is a prevalent condition among postmenopausal women, with an estimated 40% of Saudi women affected. Concurrently, type 2 diabetes mellitus (T2DM) is highly prevalent in the Qassim region, affecting 45% of individuals aged 40 and older. Despite conflicting evidence regarding the impact of T2DM on bone health, its role in OP development remains uncertain. <i>Materials and Methods:</i> This study investigates site-specific bone mineral density (BMD) variations and their metabolic correlations in postmenopausal Saudi women with T2DM. A cross-sectional study included 250 postmenopausal Saudi women, 100 without diabetes (Group 1) and 150 with diabetes (Group 2), matched for age, menopausal duration, and body mass index (BMI). BMD at the femoral neck (FN) and lumbar spine (LS) was assessed using dual-energy X-ray absorptiometry (DXA). Biochemical markers, including parathyroid hormone (PTH), alkaline phosphatase (ALP), estrogen, calcium, and HbA1c, were assessed. Statistical analyses, including chi-square tests, <i>t</i>-tests, ANOVA, Pearson correlation, and multivariate regression, evaluated BMD variations and biochemical associations. <i>Results:</i> Patients with diabetes exhibited significantly higher FN T-scores than those without diabetes (<i>p</i> = 0.001), while LS T-scores showed no significant difference. BMD distribution (normal, osteopenia, OP) did not differ between the groups (<i>p</i> > 0.05). FN T-scores correlated positively with parathyroid hormone (PTH) and alkaline phosphatase (ALP) levels, reduced estrogen, and prolonged menopause duration (<i>p</i> < 0.01) but were inversely associated with estrogen levels and menopause duration (<i>p</i> < 0.01). <i>Conclusions:</i> No significant association was found between HbA1c and BMD. Additionally, BMI demonstrated a protective effect on FN BMD. T2DM appears to influence bone metabolism without directly causing OP in postmenopausal women. Aging, menopause duration, metabolic markers (PTH, ALP, estrogen), and BMI play crucial roles in BMD variations, with a protective effect of BMI. These findings underscore the importance of site-specific BMD assessment and metabolic profiling in postmenopausal women with diabetes. Further longitudinal research is needed to elucidate the underlying mechanisms affecting bone health in postmenopausal women with diabetes.