Among patients with stage 3 chronic kidney disease (CKD), secondary hyperparathyroidism (SHPT) more frequently develops in those aged 65 years and older than in younger patients, according to researchers.
According to study findings published in International Urology and Nephrology, 49.4% of 518 patients aged 65 years and older had parathyroid hormone (PTH) levels above 65 pg/mL compared with 38.6% of younger patients, after matching by sex and estimated glomerular filtration rate (eGFR).
“We have confirmed that elderly patients, indeed, have a higher prevalence of SHPT, which may not be explained by a reduction of renal function,” Rosilene Elias, MD, PhD, of University of São Paulo School of Medicine in São Paulo, Brazil, told Renal & Urology News.
Compared with the younger group, elderly patients had higher mean serum calcium levels (9.6 vs 9.4 mg/dL) and PTH levels (65 vs 58 pg/mL) and lower mean serum phosphate levels (3.3 vs 3.5 mg/dL), and were more likely to be taking diuretics (46% vs 38%). Elderly patients with SHPT also had a lower calcium-PTH ratio (0.15 vs 0.16). A distinct relationship between calcium and PTH may contribute to SHPT in older adults, according to Dr Elias. “Whether this is a result of renal resistance to PTH or an altered set point of PTH activation/suppression by serum calcium deserves further investigation,” Dr Elias said.
She and her colleagues noted that to their knowledge, the study is the first to demonstrate that elderly patients with CKD present with a higher prevalence of SHPT when compared to a sex-matched younger population.
Elias RM and Moysés RMA. Elderly patients with chronic kidney disease have higher risk of hyperparathyroidism. Int Urol Nephrol. doi: 10.1007/s11255-017-1650-7