Racial differences in scleroderma among women in Michigan.

OBJECTIVE: To examine racial differences in disease onset, extent, manifestations, and survival among women with scleroderma.

METHODS: A retrospective cohort study of women with scleroderma, diagnosed in Michigan between 1980 and 1991, was conducted. Clinical, laboratory, and demographic data were abstracted from the patients' medical records.

RESULTS: A total of 514 women with scleroderma were identified: 117 (23%) were black and 397 (77%) were white. Among black women, the mean age at diagnosis was lower (44.5 years versus 51.5 years; P < 0.001) and diffuse disease was more common (49.6% versus 24.9%; P < 0.001) than among white women. The overall incidence of scleroderma was 14.1 per million per year: 22.5 per million per year in black women versus 12.8 per million per year in white women (P < 0.001). Pericarditis (P = 0.009), pulmonary hypertension (P < 0.001), pleural effusions (P = 0.01), myositis (P = 0.02), and an erythrocyte sedimentation rate >40 mm/hour (P < 0.001) were more frequent among black women, while white women were more likely to have digital infarctions (P < 0.001). Survival at 7 years from diagnosis was 72.5% among black women and 77.6% among white women. Age-adjusted survival was significantly reduced among black women (P = 0.033), most likely because of increased diffuse involvement. Survival among those with renal or pulmonary involvement was also significantly reduced.

CONCLUSION: Black women with scleroderma were significantly more likely than white women to develop diffuse disease, be diagnosed at a younger age, have a higher incidence of inflammatory features, and have a worse age-adjusted survival rate.