A recent study revealed that the risk (age and sex adjusted) of NL was increased by 60% in cases compared to controls. Increased risk of nephrolithiasis (NL) is a very well-known complication of gout. Though there are few comparative studies revealing the association of risk factors for NL in gout. In this cohort study, scientists investigated:
(1) the overall incidence of NL in gout patients (cases) and the general population (controls);
(2) risk and risk factors such as common co morbidities and medications for first-time NL in cases and controls separately.

A total of 168,646 were included in the study out of these the cases were n = 29,968 and age and sex-matched controls were n = 138,678. These all were separately identified from the regional healthcare database in western Sweden (VEGA). The analyzed risk factors like co morbidities and current medication use for first-time NL and socioeconomic factors were extracted from VEGA and other national Swedish registers. The follow up for cases, began on 1 January 2006 or the diagnosis of gout if this occurred later, and for controls follow begun on their index patient's first diagnosis of gout. Follow up ended on death, emigration or 31 December 2012. Both incidence rates (IR) per 1000 person-years and hazard ratios (HR) were calculated from the follow-up data. The IR calculations were performed for cases (regardless of prior NL) and their controls. HRs with the first occurrence of NL as the outcome were calculated only in those without previous NL.

The NL events were 678 (IR: 6.16 events per 1000 person-years) in cases and 2125 (IR 3.85 events per 1000 person-years) in controls, resulting in an age-sex-adjusted incidence rate ratio of 1.60. But the point estimates for predictive factors were similar in both cases and controls, but losartan increased the risk of NL only in controls i. e., HR = 1.49. Loop diuretics were found to significantly decrease the risk of NL by 30-34% in both cases and controls. Further significant predictors of NL in gout cases were obesity, diabetes and male sex and in controls male sex and kidney disease.

Moreover, none of the commonly used medications increased the risk of NL in gout patients.