Endocrine Abstracts

Background: Metabolic syndrome may be the nonclassical feature of primary hyperparathyroidism (PHPT) because an increased incidence of various glucose and lipid disorders is often observed in patients with this disease. Earlier we showed PHPT patients had higher serum triglycerides and higher rate of insulin resistance compared to the control group. Dynamics of metabolic parameters after surgery is ambiguous.

The aim: of this study was to compare metabolic parameters in patients with PHPT before and after parathyroidectomy.

Material and Methods: 24 patients with PHPT (median age 37 years [33; 41]) underwent biochemical and hormone evaluation, standard oral glucose tolerance test, euglycemic hyperinsulinemic and hyperglycemic clamps, bioelectrical impedance analysis of the body composition before and 1 year after surgery. The exclusion criteria were the GFR <60 ml/min/1.73 m², severe comorbid illness, body mass index (BMI) ≥32 kg/m², diabetes mellitus, using drugs affecting glucose, lipid and calcium balance. Control group (n=20) was sex-, age- and BMI-matched without any endocrine pathology (median serum albumin-adjusted calcium (Ca_adj) 2.24 [2.15; 2.28]mmol/l, parathyroid hormone 40.19 [31.10; 51.04]pg/ml).

Results: Except one patient who had glucose intolerance others had normal glucose metabolism according to standard lab tests. 54.2% had normal weight, 41.7% was overweight and just 1 person had obesity I, herewith 45.8% of all had over visceral fat. Insulin resistance (by M-index) was detected in 54.2% cases. PHPT patients had higher serum triglycerides (1.13 [0.94; 1.39] vs 0.79 [0.63; 1.01]mmol/l), lower M-index (5.60 [4.25; 7.45] vs 7.9 [7.0; 10.6]mg/kg*min) and higher C-peptide and insulin levels in both phases of pancreas secretion compared to the control group (P<0.05 for all). After radical parathyroidectomy we detected decreased fasting glucose (5.04 [4.63; 5.23] vs 4.69 [4.48; 5.00]mmol/l, p=0.031), uric acid (297.7 [246.4; 365.6] vs 261.58 [238.52; 350.37]μmol/l, p=0.044) levels and insulin level of second secretion phase (AUC 1150.2 [960.8; 1447.9] vs 982.0 [805.8; 1375.7], p=0.039) but any significant changes of lipid profile and M-index as well as body composition weren’t revealed. We found negative correlation between Caadj and total cholesterol levels (r=−0.50), P<0.05 as well as total fat mass and osteocalcin (r=−0.45), b-CrossLaps (r=−0.41) and magnesium levels (r=−0.43), P<0.05 in patients before surgery.

Conclusion: Changes of bone and mineral parameters in PHPT can lead to metabolic disorders. Remission of the parathyroid pathology is suspected to improve carbohydrate and purine balance but further studies are required to clarify this statement.