Table 1.

Summary of cohorts with normocalcemic primary hyperparathyroidism described in the literature.

Study	Cohort Size	Age (years)	Female (%)	Osteoporosis (%)	Nephrolithiasis (%)	Comments
Symptomatic cohorts
Lowe et al. [23]	37	58 ± 12	95	57a	14	Ionized calcium not available for all
Tordjman et al. [24]	32	61 ± 11	84	36	9	Six with hypercalciuria not responding to hydrochlorothiazide, 3 with vitamin D deficiency although hyperparathyroidism persisted despite vitamin D repletion
Amaral et al. [25]	33	64 ± 14	79	15b	18	Ionized calcium not measured
Cakir et al. [26]	18	50 ± 10	47	47	11	Ionized calcium not measured Aim of investigating glucose and lipid metabolism; no differences between patients and age-, sex-, and BMI-matched controls with respect to indicators of insulin resistance
Wade et al. [27]	8	60	63	25c	25	Surgical cohort: Five subjects had single gland disease and 3 multiple glands
Asymptomatic cohort
Garcia-Martin et al. [29]	6	56 ± 3	100d	0	0	Ionized calcium not measured Population-based cohort

Mean ± SD

Body Mass Index, BMI

^a11% with fragility fracture

^bOnly fracture history available

^c13% with fragility fracture

^dStudy design