203 Secondary hyperparathyroidism is associated with poor physical performance in older adults: results from the TUDA study

Background Vitamin D deficiency frequently leads to secondary hyperparathyroidism and is associated with frailty and sarcopenia. However, the role of hyperparathyroidism in the pathophysiology of frailty and impaired physical function is unclear. In this study, we evaluated the relationship between secondary hyperparathyroidism and poor physical performance as assessed by the Timed-Up-and-Go (TUG) test. Methods Participants were from a cross-sectional study of Irish adults aged >60 years. Those with eGFR <30 mL/min and serum calcium ≥2.5 mmol/L were excluded to avoid hyperparathyroidism due to renal impairment and primary hyperparathyroidism. We also excluded participants on drugs that may affect parathyroid hormone (PTH): (teriparatide, denosumab, activated forms of vitamin D), factors affecting physical function (glucocorticoid use: current or past >3 months and history of stroke) and those with an MMSE <24. Hyperparathyroidism was defined as a PTH ≥65 nmol/L and abnormal physical performance by TUG ≥12 seconds. The relationship between hyperparathyroidism and abnormal TUG was explored in logistic regression. Results There were 3,405 participants. 72.4% were female and mean age was 77.5 +/−7.6 years, with 36.7% having a TUG ≥12 seconds. Secondary hyperparathyroidism was significantly associated with TUG ≥12 (OR: 1.34; CI: 1.04–1.74, p = 0.026) after adjustment for age, sex, body mass index, serum 25-hydroxyvitamin D, eGFR, dairy intake, alcohol use, smoking, diabetes mellitus, cardiovascular disease (ischaemic heart disease, heart failure) and peripheral artery disease. Conclusion Secondary hyperparathyroidism was associated with a 34% increased risk of poor physical performance. Other research has demonstrated an association between elevated PTH and sarcopenia supporting a role for its direct effect on muscle function. This study highlights the importance of ensuring both adequate vitamin D status and calcium intake in older adults to reduce the risk of secondary hyperparathyroidism and its potential negative impact on the musculoskeletal system.