Insulin resistance before and after parathyroidectomy in patients with primary hyperparathyroidism--a pilot study.
BACKGROUND
Primary hyperparathyroidism (PHPT) is associated with insulin resistance and an increased cardiovascular mortality. We aimed to see if parathyroidectomy improved insulin resistance.


METHODS
Twelve PHPT patients undergoing parathyroidectomy and ten control patients undergoing non-neck surgery were recruited to the study. Fasting venous blood samples were collected immediately pre-operatively and again at five to six weeks post-operatively. Samples were assayed for plasma glucose, serum insulin, total cholesterol, triglycerides, calcium, alkaline phosphatase, magnesium, parathyroid hormone (PTH), and haemoglobin A1c (HbA1c). Insulin resistance was calculated from fasting insulin and glucose values using Homeostasis Model Assessment (HOMA).


RESULTS
Parathyroidectomy decreased serum calcium (mean pre-op = 2.85 mmol/L, post-op 2.28 mmol/L, P < 0.001) and PTH concentrations (mean pre-op = 23.33 pmol/L, post-op = 10.23 pmol/L, P < 0.001) and increased phosphate concentration. However, there was no improvement in insulin resistance in the PHPT group at between 5 and 6 weeks post-operatively (geometric mean; pre-op = 0.88 (95% CI 0.59 - 1.33) vs. post-op = 0.88 (0.66 - 1.17) P = 0.95). In the control group, an increase in serum calcium was observed post-operatively (mean pre-op = 2.29 mmol/L, post-op = 2.35 mmol/L, P = 0.03). No change in insulin resistance was observed (geometric mean; pre-op = 1.37 (95% CI 0.89 - 2.11) vs. post-op = 1.38 (0.72 - 2.67) P = 0.96).


CONCLUSIONS
In summary, no significant change in insulin resistance post-parathyroidectomy in patients with PHPT was observed. This indicates that surgical treatment of PHPT does not improve insulin resistance for patients currently selected for parathyroidectomy.
Rudman
Andrew
A
University of Dundee, Dundee, UK.
Pearson
Ewan R
ER
Smith
David
D
Srivastava
Rajeev
R
Murphy
Michael J
MJ
Leese
Graham P
GP
D000469:Alkaline Phosphatase / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002118:Calcium / Q000097:blood; D016022:Case-Control Studies; D002784:Cholesterol / Q000097:blood; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D049950:Hyperparathyroidism, Primary / Q000097:blood* / Q000601:surgery*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology*; D008274:Magnesium / Q000097:blood; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D016105:Parathyroidectomy; D010865:Pilot Projects; D018709:Statistics, Nonparametric; D014280:Triglycerides / Q000097:blood
D000469:Alkaline Phosphatase; D001786:Blood Glucose; D002118:Calcium; D002784:Cholesterol; D006442:Glycated Hemoglobin; D007328:Insulin; D008274:Magnesium; D010281:Parathyroid Hormone; D014280:Triglycerides