Background New Caledonia is a Pacific island of 270.000 inhabitants with mixed ethnicities, including Melanesians (39.1%) and Polynesians (10.2%) and people from European ancestry (27.2%).

Objectives To determine the prevalence of gout and hyperuricemia in the various ethnicities and to characterize associated factors.

Methods A 3-degree random sample of the population aged 18 to 60 years old was redressed according to the 2014 New Caledonia census. Face-to-face interviews were performed by trained nurses who used a predefined questionnaire along with planned physical measurements. All participants underwent capillary measurement of creatinine level (StatSensor) and all men and only women older than 40 years underwent uricemia testing (HumaSens). Gout was defined by a validated algorithm (1). Hyperuricemia was defined by capillary level equivalent to plasma uric acid level (PUA) >6 mg/dl (2) and/or urate lowering drug (ULD) prescription.

Results 1.144 participants (mean age 37.7 years; 50.4% men) were included. Prevalence of gout in the entire redressed sample was 3.3% (95% CI 2.2–4.9). The prevalence was 4.1% (1.8–8.9), 2.6% (1.4–4.7), 6.7% (2.5–16.8), and 1.9% (0.5–6.6) for Europeans, Melanesians, Polynesians and other ethnicities, respectively. After adjustment for age and sex, Polynesians showed higher risk for gout than Europeans (adjusted odds ratio [aOR] 4.57 [95% CI 1.3–16.7]). Prevalence of hyperuricemia, determined in 658 participants, was 67.0% (95% CI 61.9–71.6). Prevalence of hyperuricemia was greater for Polynesians (aOR 9.17 [3.2–26.4]), Melanesians (aOR 4.02 [2.2–7.2]) and other ethnicities (aOR 2.18 [1.1–4.5]) than Europeans. On univariate analysis, factors associated with gout were hyperuricemia, male gender, age, BMI, waist circumference, renal failure, hypertension, diabetes, history of major episodes of depression and cancer but not dietary factors or physical activity, despite a consistent association with BMI. Among gout and non-gout patients, 45.9% and 0.7% were receiving ULT. Overall, 29.6% of patients receiving ULD had proper control of PUA levels (≤6 mg/dl).

Conclusions As compared with Europe, in New Caledonia, the prevalence of gout and hyperuricemia was high, including in patients with European descent, as was previously reported for New Zealand (3). The prevalence of gout and hyperuricemia differed by ethnicity. For Melanesians, the prevalence of hyperuricemia was higher but risk of gout similar to that for Europeans, so factors (e.g., genetics) other than those involved in hyperuricemia may intervene in the risk of gout.

References

1. Richette et al. Ann Rheum Dis 2015;74:1684–90.

2. Fabre et al ACR meeting, Washington 2016.

3. Winnard et al Rheumatology 2012;51:901–9.

References

Disclosure of Interest None declared