Endocrine Abstracts

JOINT163

Normocalcaemic primary hyperparathyroidism(NCPHPT) is diagnosed as elevated parathyroid hormone(PTH), normal albumin-corrected serum calcium(sCa) and ionized calcium(iCa) after excluding secondary causes of PTH elevation. Parathyroid index(PF index) and calcium to phosphorous ratio(C/P ratio) are useful tools to differentiate NCPHPT from other causes of PTH elevation. We studied 40 consecutive patients with primary hyperparathyroidism(PHPT). Biochemically, serum albumin(S.Alb-gm/dl; N 3.5-5), creatinine(S.Cr-mg/dl; N 0.61-1.2), alkaline phosphatase(SAP-IU/l; 32-126), sCa(mg/dl;N 8.5-10.5), iCa(mmol/l;N 1.12-1.32), phosphorous(S.Phos- mg/dl;N 2.5-4.6), PTH(pg/ml; N 12-88), and 25 Hydroxy vitamin D (25OHD-ng/dl;N>30) were evaluated. C/P ratio (N<2.11) and PF index (N<25.8) were calculated from these parameters. Mean+SD was used to depict variables normally distributed, and median with interquartile range(IQR) for variables that do not conform to normality. The male-to-female ratio is 1:2(55+16 years of age). Results for the whole group were S. Alb 4.2(3.9-4.48); S.Cr 0.86(0.64-1.26); SAP 88.5(73.75-121.5); sCa10.82+1.58; iCa 1.42+0.22;S.Phos 3.14+0.83; S.PTH 206(140-316); 25OHD 32(25.73-43); C/P ratio3.74+1.3;PF index 54.7(34.54-108.4). The data were analyzed as the normocalcaemic group(NsCa)(sCa<10.5) (n =19) and the Hypercalcaemic group (HsCa)(sCa>10.5)(n =21). The results for NsCa were 4.44+0.43; 0.73(0.64-1.19); 78(71-89); 9.61+0.62; 1.32+0.19; 3.48+0.74; 201+117; 35.5(30-45); 2.89+0.68; 44.75(26-55.4), respectively. In HsCa group 4.1(3.45-4.25); 1.06+0.56; 102(85-160); 11.4(10.85-12.64); 1.51+0.21; 2.83+ 0.81; 284(178.4-352); 32.81+16.5; 4.51+1.26; 101(53-154), respectively. The sCa, iCa; SAP, S.Phos, PTH, C/P ratio, and PF index significantly differed between the groups(Mann Whitney P<0.005). The data were analyzed based on 25OHD-low Vit D<30(n =16) and Vit D>30(n =24) the values of sCa11.5+1.67Vs10.33+1.34(P = 0.007);iCa1.5+0.25Vs1.38(1.23-1.43)(P = 0.25); S.Phos 2.67+0.62Vs3.45+0.82(P<0.002) PTH 293+205Vs196(127-281)(P = NS); 25OHD 21+8.4Vs41.35(33.63-54.1)(P = <0.0001); C/P ratio 4.55+1.26Vs3.2+1.04(P = 0.01);PF ratio112.43+88.83Vs50.77(27.42-56)(P = 0.012)(Mann Whitney P). The data were analyzed based on normal sCa, iCa, and 25OHD (rubric criteria for NCPHPT;n =8), and the results were 4.41+0.47; 83(74-92); 1.13+0.44; 9.23+0.52; 1.19+0.07; 3.7+0.65; 36.8(34-65); 2.57+0.54; 40.67+16.55, respectively. The data were grouped as NCPHT; normal 25OHD, calcium but elevated ionic calcium(n =7) and classic PHPT(n =7). The sCa, iCa, SAP, CP ratio, and PF index were statistically significant in all three groups(Kruskal Wallis H P<0.001). The highest values were obtained for PHPT, and the lowest for the NCPHT category. Bone mineral density of the lumbar spine, hip, and, non-dominant forearm, were in the osteoporosis range among all categories and were not significantly different. All patients had parathyroid adenoma, which was confirmed histologically after surgery. The weight of the adenoma ranged from 26 mg to 15 gms. The C/P ratio and PF index were above the normal and predicted the hyperparathyroidism status across the spectrum; whole group, normocalcaemic and hypercalcaemic groups and normal Vs low vitamin D