GLUCOSE TOLERANCE AND INSULIN SENSITIVITY IN PRIMARY HYPRPARATHYROIDISM AND HYPOPARATHYROIDISM.

Narendra Kotwal, R. Muralidharan, A. Bhansali, R.J.Dah, Deptt. Endocrinology, PGIMER, Chandigarh.

Changes in plasma glucose (PG) and insulin sensitive index (ISI) have been variably reported in patient with parathyroid disease, however, no study has so far been reported from India.  In order to assess the effects of PTH, Ca and PO4 on PG and ISI, we studied these parameter in patients with 10 hyperparathyroidism (10HPT) and hypoparathyroidism (10 from each category) before and at 3 months after effective treatment and normalization of biochemical profile. Serum Ca, PO4, alk, phosphatase, PTH (whole molecule) and urinary Ca, PO4 were estimated for each patient’s diagnostic work up and correlation with PG profile and ISI at diagnosis and follow up.  Oral glucose tolerance and rapid insulin tolerance tests were done for assessing glucose tolerance and ISI.  ISI was also calculated by HOMA.  Serum calcium is 10 HPT was 12.4± 2.5(10.80 – 13.4mg/dl) which normalised after surgery to 9.7 ± 1.1 (8-11 mg/dl).  Consequently there was lowering of serum IRI (from 86 ± 28.8 to 58± 27.4pmol/l, p<0.1), PG (from 102± 25.3 to 93± 18.3 mg/dl, P<0.1) and ISI (HOMA, from 2.7 ± 0.9 to 1.6 ± 0.6 p< 0.05).  In hypoparathyroidism, low serum calcium and high phosphate were normalized with Ca and Vitamin D.  Serum Ca increased from 6.5 ± 0.8 to 9.2 ± 0.6 mg/dl (P<0.01), PO4 decreased from 6.1 ± 3.5 to 4.4 ± 0.7 mg/dl (p<0.01), IRI increased from 69 ± 32.4 to 156 ± 25.6 pmol/l (p>0.1), PG increased from 101 ± 24.5 to 117 ± 30.1 mg/dl (p>0.01) and ISI increased from 2.2 ± 1.1 to 2.4 ± 1.2 (HOMA, p>0.05) was associated with serum IRI 69± 32.4pmol/l, PG 101 ± 24.5 mg/dl and ISI 2.2 ± 1.1.

These data indicate significant influence of PTH on insulin secretion and action and reversibility of insulin secretory and functional defects with correction of metabolic abnormalities in parathyroid disease.