An update on clinical and genetic features of diuretic-associated gout
Hyperuricemia is one of the most common findings in patients treated with loop or thiazide diuretics and patients might develop gouty arthritis over a period of time. Treatment of asymptomatic hyperuricemia may not be necessary but when it becomes complicated, it requires treatment. For an ideal treatment approach, it is important to understand the clinical and genetic features of diuretic-associated gout.
A group of investigators tried to evaluate the clinical and genetic features of diuretic-associated gout in one of the recent studies. Detailed clinical assessment of 1365 patients recruited from primary and secondary care, fulfilling the 1977 ARA gout classification criteria, was done. Diuretic use was also recorded and was confirmed by electronic dispensing data [n = 426 (31.2%) on diuretics]. Genotyping was done on gout-associated single nucleotide polymorphisms. Using a case-control study design, clinical and genetic features of diuretic-associated gout were analyzed.
There were more women, higher rates of comorbid conditions, higher BMI and lower estimated glomerular filtration rate in diuretic patients as compared to non-diuretic patients. In both the groups, duration of gout disease, gout flares frequency and presence of tophi was similar. Age of gout presentation and serum urate was higher in patients on diuretics. In diuretic group, the ABCG2 rs2231142 risk allele was less frequent (36.1%) compared to patients not on diuretics (47.6%, P = 1.2 × 10-4). The differences in ABCG2 were observed in both men and women with gout.
Diuretic-associated gout is surely a complex medical condition. Though, gout occurs usually at an advanced age and in patients on diuretics, serum urate concentrations are higher, other clinical features of gout are similar. As far as genetics is concerned, the current findings propose less dominant role of genetic factors in diuretic-associated gout compared to primary gout.