Incidence and prevalence of systemic lupus erythematosus among Arab and Chaldean Americans in southeastern Michigan: the Michigan Lupus Epidemiology and Surveillance Program.

OBJECTIVES: We assessed the burden of systemic lupus erythematosus (SLE) among Arab and Chaldean Americans residing in southeast Michigan. METHODS: For those meeting SLE criteria from the Michigan Lupus Epidemiology and Surveillance Registry, we determined Arab or Chaldean ethnicity by links with demographic data from birth certificates and with a database of Arab and Chaldean names. We compared prevalence and incidence of SLE for Arab and Chaldean Americans with estimates for non-Arab and non-Chaldean American Whites and Blacks. RESULTS: We classified 54 individuals with SLE as Arab and Chaldean Americans. The age-adjusted incidence and prevalence estimates for Arab and Chaldean Americans were 7.6 and 62.6 per 100 000, respectively. Arab and Chaldean Americans had a 2.1-fold excess SLE incidence compared with non-Arab and non-Chaldean American Whites. Arab and Chaldean American women had both significantly higher incidence rates (5.0-fold increase) and prevalence estimates (7.4-fold increase) than did Arab and Chaldean American men. CONCLUSIONS: Recognizing that Arab and Chaldean Americans experience different disease burdens from Whites is a first step toward earlier diagnosis and designing targeted interventions. Better methods of assigning ethnicity would improve research in this population.

Population-based incidence and prevalence of systemic lupus erythematosus: the Michigan Lupus Epidemiology and Surveillance program.

OBJECTIVE: To estimate the incidence and prevalence of systemic lupus erythematosus (SLE) in a sociodemographically diverse southeastern Michigan source population of 2.4 million people. METHODS: SLE cases fulfilling the American College of Rheumatology classification criteria (primary case definition) or meeting rheumatologist-judged SLE criteria (secondary definition) and residing in Wayne or Washtenaw Counties during 2002-2004 were included. Case finding was performed from 6 source types, including hospitals and private specialists. Age-standardized rates were computed, and capture-recapture was performed to estimate underascertainment of cases. RESULTS: The overall age-adjusted incidence and prevalence (ACR definition) per 100,000 persons were 5.5 (95% confidence interval [95% CI] 5.0-6.1) and 72.8 (95% CI 70.8-74.8). Among females, the incidence was 9.3 per 100,000 persons and the prevalence was 128.7 per 100,000 persons. Only 7 cases were estimated to have been missed by capture-recapture, adjustment for which did not materially affect the rates. SLE prevalence was 2.3-fold higher in black persons than in white persons, and 10-fold higher in females than in males. Among incident cases, the mean ± SD age at diagnosis was 39.3 ± 16.6 years. Black SLE patients had a higher proportion of renal disease and end-stage renal disease (ESRD) (40.5% and 15.3%, respectively) as compared to white SLE patients (18.8% and 4.5%, respectively). Black patients with renal disease were diagnosed as having SLE at younger age than white patients with renal disease (mean ± SD 34.4 ± 14.9 years versus 41.9 ± 21.3 years; P = 0.05). CONCLUSION: SLE prevalence was higher than has been described in most other population-based studies and reached 1 in 537 among black female persons. There were substantial racial disparities in the burden of SLE, with black patients experiencing earlier age at diagnosis, >2-fold increases in SLE incidence and prevalence, and increased proportions of renal disease and progression to ESRD as compared to white patients.

Polybrominated biphenyls, polychlorinated biphenyls, body weight, and incidence of adult-onset diabetes mellitus.

BACKGROUND: Prior studies have reported an increased risk of diabetes related to polychlorinated biphenyl (PCB) exposure. No study has yet investigated whether polybrominated biphenyls (PBBs), which are similar in chemical structure, increase the incidence of diabetes. METHODS: The Michigan PBB cohort was established in 1976 and surveyed again in 1991-1993 and in 2001. PBB and PCB serum levels were measured from blood collected at enrollment. To determine the incidence of adult-onset diabetes, we analyzed cohort members without diabetes at enrollment, ages 20 years and older, with known PBB and PCB levels, who participated in at least 1 follow-up survey (n = 1384). Using Poisson regression, we determined the incidence density ratio (IDR) of diabetes for different serum levels of PBB and PCB, controlling for age, body mass index, smoking, and alcohol consumption at enrollment. RESULTS: Analyzing 25 years of follow-up data, we did not find that higher PBB serum levels were a risk factor for the incidence of diabetes mellitus. However, in women, but not in men, higher PCB serum levels were associated with increased incidence of diabetes (IDR = 2.33; 95% confidence interval = 1.25-4.34 in the highest PCB group compared with the lowest). In both men and women, overweight and obesity increased the diabetes incidence. CONCLUSIONS: We found no association between PBB serum levels and diabetes incidence. In women, there was a positive linear association of diabetes incidence with PCB serum levels at enrollment. This finding is in agreement with 2 prior studies indicating a higher relative risk of diabetes in PCB-exposed women.