Influence of alcohol intake, cigarette smoking, and occupational status on idiopathic osteonecrosis of the femoral head.

An epidemiologic study compared 112 patients with idiopathic osteonecrosis (ON) of the femoral head having no history of systemic corticosteroid use and 168 hospital controls. Patients and controls were matched for gender, age, ethnicity, hospital, and time of initial diagnosis. The role of alcohol intake, cigarette smoking, and occupational status was assessed in relation to the development of ON. The relative risk (RR), the measure of association between ON and the risk factors, was statistically adjusted for the potential confounding effects of other factors by the conditional logistic regression model. An elevated risk for regular drinkers (RR = 7.8, p less than 0.001) and a clear dose-response relationship was noted (test for trend; p less than 0.001): the RRs were 3.3, 9.8, and 17.9 for current consumers of less than 400, 400-1000, and greater than or equal to 1000 ml/week of alcohol, respectively. A significantly increased risk was found for current smokers (RR = 3.9; p less than 0.05). However, the cumulative effect of smoking was not evident. No increased risk was found for obesity or for heavy physical work. Regarding causation of ON, this study confirmed the consistent association with excessive alcohol intake and suggested the immediate untoward effects of smoking. The role of heavy physical work as a form of mechanical stress was not correlated with ON.