Prevalence and determinants of secondary hyperparathyroidism: IMOS-2021

(β = 6.38; 2.57 to 10.18) and 60-90 (β = 3.62; 1.58 to 5.67) were associated with higher PTH levels. Additionally, phosphorus level (β = -2.36; -4.38 to -0.34), and male sex (β = -4.54; -6.77 to -2.31) was independently associated with lower PTH concentrations. This study provides nationally representative evidence on SHPT prevalence and its determinants in Iranian adults. Obesity, low calcium intake, and chronic kidney disease were positively associated with SHPT and PTH elevation, while Vitamin D sufficiency, phosphorus level, and male sex were negatively associated with the condition. These findings underscore the importance of screening and addressing modifiable factors to reduce SHPT in aging populations.