#6875 COMPLICATIONS AND TREATMENT OF HYPERCALCIURIA IN FAMILIAL HYPERKALAEMIC HYPERTENSION (FHHT)

Abstract Background and Aims Hypertension is frequently associated with hypercalciuria1, nephrolithiasis2 low bone mineral density. Familial Hyperkalaemic (FHHt) causes hypercalciuria3, although complications of this are not reported. Method We examined a cohort 9 patients genetically confirmed FHHt. Biochemical, radiological, clinical data was obtained in before after thiazide treatment. All gave informed consent. The study had ethics committee approval. Data were compared using paired t tests. Results 5 the female (median age 41.7 years). genetic diagnosis all patients, variants KLHL3, 3 WNK4, one variant WNK1 (Table 1). Pre-treatment potassium high 5.6 IQR 5.2-6.2 mmol/L). calcium normal range (2.34 2.29-2.38 There significant hypercalciuria raised urinary calcium/creatinine ratio (0.69 0.41-1.13). However, PTH (4 3.95-4.35 pmol/L), phosphate (1.15 1.25mmol/L) alkaline phosphatase (57 45-84 mmol/L) range. Thiazide treatment significantly reduced (calcium/creatinine 0.15 0.05-0.29 p = 0.04) as well serum (3.9 3.5-4.4 mmol/L 0.0167) Patients also developed hypercalciuria. kidney stones demonstrated on cross-sectional imaging (Figure One these (male, 30 years old) DXA criteria for osteoporosis (T score Femoral neck -1.5, lumbar spine -2.4). Conclusion This first case series to demonstrate (i.e. stones) that normalises excretion. may have utility FHHt even if hypertension or hyperkalaemia problematic order avoid