Uterine myomas and smoking. Results from an Italian study.
OBJECTIVE
To evaluate the relationship between smoking and uterine myomas requiring surgery.


METHODS
We conducted a case-control study in Milan between 1986 and 1992. Cases were 476 patients under 55 years of age with histologically confirmed myomas. Controls were 1,283 women admitted to the hospital for a spectrum of acute, other-than-gynecologic, hormonal or neoplastic conditions (30% trauma, 25% nontraumatic orthopedic conditions, 25% surgical, 20% other miscellaneous).


RESULTS
Cases were less frequently current smokers (22%) than controls (32%). In comparison with never smokers, the multivariate relative risk (RR) for myomas was 0.5 (95% confidence interval [CI], 0.4-0.7) in smokers. Ex-smokers were 10% of cases versus 7% of controls (RR 1.2, 95% CI 0.9-1.8). No clear trend in risk was observed with the number of cigarettes smoked per day or duration of smoking and risk of fibroids. The estimated RRs were largely consistent when separate analyses were performed in strata of age and other selected covariates, including indices of body weight.


CONCLUSIONS
Current smoking seems to reduce the risk of myomas.
Parazzini
F
F
Istituto di Ricerche, Farmacologiche, Mario Negri, Milan, Italy.
Negri
E
E
La Vecchia
C
C
Rabaiotti
M
M
Luchini
L
L
Villa
A
A
Fedele
L
L
D000328:Adult; D000375:Aging / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D016022:Case-Control Studies; D016001:Confidence Intervals; D003276:Contraceptives, Oral; D004522:Educational Status; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D007889:Leiomyoma / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology; D008875:Middle Aged; D015999:Multivariate Analysis; D010298:Parity / Q000502:physiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D014594:Uterine Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000503:physiopathology
D003276:Contraceptives, Oral