Endocrine Abstracts

Introduction: Secondary hyperparathyroidism (SHPT) develops more frequently in the elderly. The high prevalence of chronic kidney disease and inappropriate vitamin D status are among the predisposing factors. The aim of this study is to assess the prevalence of SHPT, chronic kidney disease (CKD) and vitamin D status in a representative group of Polish elderly population.

Objective: The study was carried out as a part of the nationwide PolSenior project (medical, psychological and socioeconomic aspects of aging in Poland) in the population of randomly selected 5695 participants (2899 males and 2796 females) using the national PESEL database (the National Electronic System of Population Records). Serum calcium, phosphates, creatinine, 25-OH-D3 and PTH concentrations, as well as albumin to creatinine ratio in urine were assessed in 4270 participants accounting for 75.0% of the study group. SHPT was diagnosed in participants with normal (8.4–10.0 mg/dl) or decreased (<8.4 mg/dl) corrected serum calcium concentration and increased (>65 pg/ml) intact PTH level. Estimated glomerular filtration rate (eGFR–CKD–EPI) below 60 ml/min per 1.73 m² or albuminuria ≥ 30 mg/g creatinine was interpreted as CKD. Low vitamin D status was ranked as hypovitaminosis (20–29.9 ng/dl), insufficiency (10–19.9 ng/dl) or deficiency (<10 ng/dl).

Results: Among the studied participants, 540 (12.6%) subjects were identified as having SHPT. The prevalence of SHPT in the Polish elderly population was estimated at 10.43%. It was increasing with age from 4.39% in the subjects aged 55–59, through 6.07% in those aged 65–69, 8.61% in those aged 70–74, 13.49% in those aged 75–79, 15.48% in those aged 80–84, 17.786% in those aged 85–89, to 25.97% in the group aged 90 years or more. Impaired eGFR was found in 267 (49.4%), albuminuria in 127 (23.5%) and CKD in 310 (57.4%) of participants with SHPT, while hypovitaminosis D was demonstrated in 150 (27.8%), vitamin D insufficiency in 147 (27.2%), and deficiency in 32 (5.9%). CKD or low vitamin D status was found in 82.6% of SHPT causes. Improper serum vitamin D concentration was found in 62,3% of participants with CKD.

Conclusions: Low serum vitamin D concentration is frequently observed in elderly patients with chronic kidney disease and secondary hyperparathyroidism.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.