Hmong Gout Incidence

Session: Fellows-in-Training Posters

Presentation: F23 – Gout in the Hmong in US Presents at a Young Age and is More Severe Compared to Caucasian Controls

Category: 14. Metabolic and crystal arthropathies

Author(s): Salman Waheeduddin1, Kathleen Culhane-Pera2, Jasvinder A. Singh3, Elie Gertner4. 1University of Minnesota, Minneapolis, MN; 2West Side CHS, Saint Paul, MN; 3University of Minnesota, VAMC, Minneapolis, MN; 4University of Minnesota Regions Hospital, Health Partners, Saint Paul, MN

Abstract:
Purpose: The Hmong population, an ethnic group from South Asia, that numbers around 200,000 in the U.S., has an earlier development and increased risk of obesity, hypertension and diabetes 1, factors that increase the risk of hyperuricemia and gout. We describe the demographic and clinical characteristics of the Hmong patients in the U.S. with gout.

Methods: We performed a retrospective chart review of Hmong and Caucasians (controls) with gout from 1/2001- 3/2008 in a large health system (HealthPartners) in St Paul, Minnesota. Since all Hmong patients can be identified with 18 unique clan names, we could easily identify study patients. We confirmed the ethnicity in the electronic medical records and did not match the controls for age because of a strong clinical suspicion regarding an earlier age of onset of gout in the Hmong. Clinical characteristics were compared between the Hmong and Caucasian using chi-square and t-tests. Univariate and multivariable-adjusted logistic regressions compared the association of Hmong ethnicity as the main predictor of interest with presence of tophaceous gout. Tophaceous gout was defined as documentation of tophi in physician notes. Hierarchical logistic regression models controlled for ethnicity alone, and with other variables.

Results: From the cohort of 111 Hmong and 114 Caucasian patients with an ICD-9 for gout we identified 72 Hmong patients and 53 Caucasian controls using ACR criteria. The Hmong group was younger (53.61 vs. 68.4 yrs, p=<0.001), had earlier onset of symptoms (38 vs 58.7 yrs, p<0.00, 28.3% being <30yrs of age) leaner (BMI 28.4 vs. 30.4 p= 0.011), had higher mean serum uric acid (SUA) levels during follow-up (9.2 vs. 7.8 mg/dl, p=<0.001), more tophaceous gout (38.9% vs. 15.1%, p=0.004) and hand tophi (27.8% vs. 7.5% p=0.005).
Hmong ethnicity was significantly associated with risk of tophaceous gout, with odds ratio (95% CI) of 3.6 (1.6, 8.3). After multivariate-adjustment for duration of gout symptoms, BMI, renal function, hypertension, gender, alcohol and diuretic use, Hmong ethnicity was no longer significant risk factor for tophaceous gout (table 1).

Table 1: Predictors of Tophaceous Gout in the Multivariate model

			95% CI
Variables	p	OR	Lower	Upper
Sex	0.252	0.011	0.000	24.96
Ethnicity	0.74	1.69	0.074	39.032
Duration of Symptoms	0.027	1.98	1.081	3.647
>7 alcohol drinks /wk	0.59	0.26	0.002	34.89
Diuretic use	0.998	NA	NA	NA
BMI at onset or least recent	0.32	1.22	0.82	1.811
Hypertension	0.72	0.464	0.007	32.84
Median GFR during follow up	0.94	0.99	0.84	1.17

Conclusions: Hmong patients present with more severe disease and have an earlier onset of gout symptoms. Severity of gout in Hmong is accounted in part by the duration of gout symptoms. Aggressive and early treatment of Hmong patients with gout is indicated.
References
1. Her C. Wisc Med J. 2005; 104:70-7.
Research Method: Observational
Type of Trial: Epidemiologic or Observational
Phase: Not Applicable