Habitual fish oil supplementation, genetic susceptibility of kidney stones and the risk of new-onset kidney stones

OBJECTIVE

We aimed to assess the association between habitual fish oil use and new-onset kidney stones in participants with different levels of genetic risks of kidney stones.

METHODS

477,311 participants free of kidney stones at baseline from the UK Biobank cohort were included. Fish oil use was collected by both food frequency questionnaires and 24-h dietary recalls. A genetic risk score (GRS) for kidney stones was calculated based on 20 single-nucleotide polymorphisms associated with kidney stones. The primary outcome was new-onset kidney stones.

RESULTS

During a median follow-up of 12.0 years, 5,637 cases of kidney stones were documented. Participants with high genetic risks of kidney stones had a higher risk of new-onset kidney stones (vs. low or intermediate risks; adjusted HR, 1.52; 95 %CI:1.44–1.60). Compared with non-users, habitual use of fish oil was associated with a lower risk of new-onset kidney stones (adjusted HR, 0.84, 95 %CI, 0.78–0.92) in participants with low or intermediate genetic risks, but not in those with high genetic risks of kidney stones (adjusted HR, 1.02, 95 %CI, 0.93–1.12; P-interaction =0.001). Among those with low or intermediate genetic risks of kidney stones, compared with fish oil constant nonusers, the adjusted HRs (95 %CI) for kidney stones were 0.89 (0.75–1.06), 0.72 (0.58–0.90), and 0.79 (0.64–0.97), for fish oil occasional users, modestly constant users, and moderately and highly constant users (P for trend=0.001), respectively.

CONCLUSIONS

Habitual fish oil use was associated with a lower risk of new-onset kidney stones in participants with low or intermediate genetic risk of kidney stones.