RALUCA ALEXANDRA TRIFANESCU, DAN SOARE, CATALIN CARSTOIU, GHEORGHE POPESCU, ALINA MIHAELA PASCU, VLADIMIR POROCH, SEBASTIAN TOMA, CATALINA POIANA MILD CHRONIC HYPONATREMIA AND OSTEOPOROTIC FRACTURES RISK IN ELDERLY
Low serum sodium levels were associated with increased prevalence of osteoporosis and fractures. The aim of the study was to assess the relationship between serum sodium and bone mineral density and/or osteoporotic fractures’ prevalence in elderly people. A total number of 260 patients (23 men / 237 women), aged 66.5 ± 12.8 years, were retrospectively assessed. Serum sodium levels were measured in all patients. Bone mineral density (BMD) was measured by dual X-ray absorptiometry (DXA). Results: serum natremia was 140.3 ± 4.4 mmol/L; prevalence of hyponatremia was 7.3%; frailty fractures were present in 117 out of 260 patients (45%). Patients with fractures had lower serum sodium levels as compared to patients without fractures (139 ± 3.9 vs. 141.5 ± 4.6 mmol/L, p < 0.001). Patients with osteoporosis (n = 179) also showed lower natremia as compared to patients with normal BMD and osteopenia (n = 81): 139.9 ± 4.7 vs. 141.2 ± 3.8 mmol/L, p = 0.035. In patients admitted in the hospital for fractures (n = 92), prevalence of hyponatremia was 13.04%. Hyponatremic patients had significantly higher prevalence of fractures (73.7% vs. 42.7%, p = 0.0147) as compared to normonatremic patients. Odds ratio (OR) for fractures in patients with hyponatremia was 3.75 <95% C.I.: 1.3-10.75>, p = 0.0138; OR for hip fractures in patients with hyponatremia was 3.65 <95% C.I.: 1.38-9.64>, p = 0.0089. Both incidence and prevalence of hyponatremia increase with age, especially in patients treated with diuretics. Several clinical studies found an association between mild chronic hyponatremia in elderly and increased odds ratio of osteoporosis at the total and at femoral neck; the study also showed an increased odds ratio for all fractures and for hip fractures in hyponatremic patients. Elderly people at risk of osteoporotic fractures should have sodium serum measured.
Keywords: hyponatremia, osteoporosis, fall-related fractures, bone remodelling, frailty