Risk associated behavior in premorbid multiple sclerosis: A case-control study.

BACKGROUND

It is generally accepted that individuals who subsequently develop MS are more likely to be smokers, have suffered glandular fever and to have a low blood vitamin D level. Previous research suggested that a unifying premise is risk-associated behavior before MS onset. This survey explores several health-adverse premorbid behaviors using a case-control design.

METHODS

A questionnaire was completed by 94 patients with clinically definite MS. Their responses were compared to a control group of 59 who were patients with benign headache. Questions explored pre-symptomatic experience of: (a) alcohol, smoking, substance abuse, glandular fever; (b) blood transfusion; (c) hazardous sport, gambling (d) sexual history, gynecologic infection, number of pregnancies, terminations of pregnancy. Data were adjusted for age of first symptoms, gender and smoking.

RESULTS

Compared to the headache group, MS subjects showed significant differences prior to symptom onset, adjusted for age of first symptoms, gender and smoking, with odds ratios for reporting or means and 95% confidence intervals as follows: (a) consuming alcoholic drinks, OR 6.91 (1.74 to 27.45; p=0.006) and at an earlier age, mean 16.9y (16.4 to 17.5; p=0.046) (b) cigarette smoking, OR 2.24 (1.09 to 4.59; p=0.028) and to have smoked more per day, mean 9.45 (5.55 to 13.35; p=0.001) (c) history of glandular fever/infectious mononucleosis, OR 3.07 (1.11 to 8.49; p=0.031); (d) consumed recreational drugs, OR 3.90 (1.32 to 11.50; p=0.014), notably cannabis, OR 4.10 (1.40 to 12.09; p=0.011); (e) used a car seat belt, OR 4.45 (1.43 to 13.83; p=0.010); (f) attended all-night parties, OR 2.45 (1.12 to 5.36; p=0.025); (g) sunbathed, OR 2.770 (1.02 to 7.52; p=0.046); (h) had more sexual partners, mean 3.97 (2.00 to 5.95; p<0.001), more pregnancies, mean 1.43 (0.99 to 1.86; p=0.015) and one or more terminations of pregnancy, OR 5.05 (1.003 to 25.386; p=0.049).

CONCLUSION

All but one of the statistically significant variables (use of car seat belt) supports our hypothesis that MS subjects lead a riskier premorbid lifestyle. Strong associations were found for smoking, alcohol and glandular fever as suggested by others. Novel associations were found for recreational drug use; attending all-night parties; gambling on the lottery; more sexual partners, more pregnancies and one or more terminations of pregnancy. Such behavior during the MS prodrome may expose an individual to a variety of hostile environmental agents.