Endocrine Abstracts

Background

The nonclassical complications of primary hyperparathyroidism (PHPT) can include metabolic syndrome associated with cardiovascular diseases. According to clinical studies, an increased incidence of diabetes mellitus, insulin resistance, obesity, dyslipidemia and other disorders are observed in patients with PHPT regardless of the severity of the disease. The aim of this study is to estimate metabolic parameters in patients with PHPT compared to healthy volunteers.

Material and methods

19 patients with PHPT (15 women, 4 men; median age 36years [30; 40]) underwent biochemical and hormone evaluation, standard oral glucose tolerance test with 82.5g glucose monohydrate, euglycemic hyperinsulinemic clamp and bioelectrical impedance analysis of the body composition before surgery. The exclusion criteria were the GFR < 60 ml/min/1.73 m², severe comorbid illnesses, body mass index (BMI) ≥ 32 kg/m², diabetes mellitus, using drugs affected glucose and calcium balance. Control group (n = 19) was sex-, age- and BMI-matched without pathology of parathyroid glands (median serum albumin-adjusted calcium (Ca_adj) 2.25 mmol/l [2.19; 2.29], PTH 38.3 pg/ml [29.6; 43.5]).

Results

All patients had symptomatic PHPT (median Ca_adj 2.8 mmol/l [2.61; 2.96], PTH 137.8 pg/ml [106.1; 209.5]) and 18 had normal glucose metabolism according to standard tests (in 1 man glucose intolerance) – median fasting plasma glucose 5.06 mmol/l [4.77; 5.24], 2-hour postload plasma glucose 5.51 mmol/l [4.56; 6.88], HbA1c (NGSP) 5.3% [5.0; 5.5]. 10 patients (52.6%) had normal weight, 8 (42.1%) – overweight and 1 person (5.26%) – obesity I, besides 36.8% patients had features of visceral obesity. PHPT patients had higher serum triglycerides and lower 25(OH)D₃ level comparing to control group (1.19 [0.93; 1.32] vs 0.8 [0.66;1.0] mmol/l, P = 0.001 and 18.6 [12.8;21.9] vs 24.5 [19.5;42.2] pg/ml, P = 0.018 respectively). However the clamp showed a significant lower M-index in PHPT group (5.48 [4.3; 7.47] vs 7.5 [6.45; 10.99], P = 0.005), insulin resistance was detected in 52.6% patients. We found significant correlations between PTH and triglycerides (r = 0.43) and total cholesterol levels (r = –0.44), P < 0.05 as well as Ca_adj and fasting plasma glucose (r = 0.36) and triglycerides (r = 0.60), P < 0.05 in general group. M-index correlated with serum phosphorous level (r = 0.46), triglycerides (r = –0.53), BMI (r = –0.43), %-total fat mass (r = –0.4) and visceral fat area (r = –0.45) in general group, P < 0.05 for all. But these data were not confirmed in the PHPT group except a correlation of M-index with triglycerides level (r = –0.59, P < 0.05).

Conclusion

Our results demonstrated the potential effect of PHPT on metabolic parameters, but further studies are required to clarify these links.