title: Insulin sensitivity is inversely correlated with plasma intact parathyroid hormone level.
abstract: Abnormal glucose metabolism and a high prevalence of diabetes have been reported in patients with primary and secondary hyperparathyroidism. We hypothesize that plasma intact parathyroid hormone (iPTH) level is a determinant of either insulin sensitivity or beta-cell function. The study included 52 normotensive, healthy subjects with glucose tolerance. Insulin sensitivity and beta-cell function were assessed using a hyperglycemic clamp. Fasting plasma iPTH was determined. The relationships between its level and insulin sensitivity index and beta-cell function were examined. Insulin sensitivity index was inversely correlated with plasma iPTH level (r2 = .104, P = .020). The first phase insulin response was positively correlated with plasma iPTH level (r2 = .098, P = .023), but no correlation existed with the second phase insulin response. After adjusting for age, gender, ethnicity, and waist-to-hip ratio, plasma iPTH level was an independent determinant of insulin sensitivity index (P = .019). However, no independent relationship between plasma iPTH level and beta-cell function (the first phase and second phase insulin response) was found. In normotensive, glucose-tolerant, and healthy subjects, plasma iPTH level accounts for 10.4% of the variation in insulin sensitivity index. For each pg/mL increment in plasma iPTH level, there is a decrease of 0.247 micromol/L/m2/min/pmol/L in insulin sensitivity index. Although the molecular basis of this relationship is not clear, our results indicate that plasma iPTH level is inversely correlated with insulin sensitivity index.
authors.affiliation: Department of Medicine, Univeristy of California, Los Angeles, School of Medicine, USA.
authors.forename: K C
authors.initials: KC
authors.lastname: Chiu
authors.forename: L M
authors.initials: LM
authors.lastname: Chuang
authors.forename: N P
authors.initials: NP
authors.lastname: Lee
authors.forename: J M
authors.initials: JM
authors.lastname: Ryu
authors.forename: J L
authors.initials: JL
authors.lastname: McGullam
authors.forename: G P
authors.initials: GP
authors.lastname: Tsai
authors.forename: M F
authors.initials: MF
authors.lastname: Saad
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D012016:Reference Values
chemical_list: D010281:Parathyroid Hormone