Data mining: Biological and temporal factors associated with blood parathyroid hormone, vitamin D, and calcium concentrations in the Southwestern Chinese population.

BACKGROUND

Parathyroid hormone (PTH) and vitamin D plays a major role in calcium (Ca) homeostasis and bone turnover. The purpose of this study was to assess which factors (sex, age, time of blood sampling, season of the year, temperature and sunshine hours (SHH)) had the greatest impact on plasma PTH, 25-OH-VitD, and Ca levels, and then whether these effects were clinically acceptable in a large number of Southwestern Chinese subjects.

METHOD: The data was from West China Hospital Health Examination Center, Sichuan University from April 1, 2018 to June 30, 2019. A total of 18,664 physical examination subjects were included. PTH and 25-OH-VitD were measured by a Roche Cobas e 601, and Ca was measured by a Roche Cobas 8000. Linear regression models were used to assess correlations between PTH, 25-OH-VitD, Ca and the above factors.

RESULTS

The concentrations of serum PTH in females were significantly higher than those in males, while the 25-OH-VitD and Ca were opposite. The concentration of PTH in data collection decreased in summer and increased in spring. The concentration of 25-OH-VitD decreases in spring and increases in autumn. PTH concentrations were negatively correlated with last month temperature and SHH, while 25-OH-VitD were opposite. Linear regression showed that season may be the main factor affecting serum PTH and 25-OH-VitD levels, and these effects were not clinically acceptable.

CONCLUSION

In order to avoid influencing clinicians' investigation of suspected hyperparathyroidism and hypovitaminosis, reference intervals for PTH, 25-OH-VitD, and Ca should be established, taking into account sex, age and the season.