Serum intact parathyroid hormone in a random population sample of men and women: relationship to anthropometry, life-style factors, blood pressure, and vitamin D.

Intact parathyroid hormone (PTH) in serum was determined in a random population sample and was related to age, sex, body composition, life-style factors, blood pressure, blood lipids, plasma fibrinogen, and serum IGF-1, osteocalcin, and vitamin D. Within the framework of the WHO MONICA Project in the city of Göteborg, Sweden, 181 men and 166 women aged 25-64 years were studied. Intact PTH concentrations varied with age but were similar in both sexes (range 4-82 ng/liter) [mean (+/- SD) 23.8 +/- 10.4 ng/liter in men and 25.1 +/- 10.6 ng/liter in women]. Intact PTH concentrations increased with increasing age, body mass index, systolic blood pressure, and 1,25(OH)2D3 and decreased with increasing 25(OH)D3 in all subjects. Additionally, in men, intact PTH correlated positively to diastolic blood pressure and negatively to coffee consumption. In women, PTH also correlated negatively to smoking and IGF-1. In a multivariate analysis including all variables, age lost its significance. In both sexes there were independent positive relations between intact PTH and body mass index and 1,25(OH)2D3, and negative relations between PTH and smoking habits as well as 25(OH)D3; among men there was also negative relations between PTH and coffee consumption. The results indicate that life-style factors such as smoking and coffee consumption decrease the serum concentration of intact PTH, and the same effect is seen in individuals with low body mass index. Coffee intake, smoking, and low body mass index are also known to adversely affect bone mineral content, highlighting the relationship between PTH and bone metabolism.