To Örebro University

Study Design: Cross-sectional study with two age cohorts.

Objective: To assess whether women receiving hormone replacement therapy after menopause have a higher prevalence of back problems than women who do not receive such treatment.

Background: Back pain is a common medical problem: throughout life and especially during pregnancy. Hormonal factors have been proposed as a possible contributor.

Patients and Methods: A validated postal questionnaire was sent in early 1995 to all 1324 women of 55 years and 56 years of age residing in Linkoping, Sweden. This questionnaire included questions about current rent hormone replacement treatment, previous and current back problems, medical care for back problems, parity, exercise and smoking habits, and occupation.

Results: The questionnaire was returned by 84.7% of the women. There was a significant, albeit weak, positive association between current use of hormone replacement treatment and low back pain. Previous back problems during pregnancy was a strong risk factor for current back pain, whereas neither current smoking nor regular physical exercise was a risk factor according to multiple logistic regression analysis. The interaction of smoking and an occupation involving heavy lifting significantly affected back pain.

Conclusions: Women receiving hormone replacement treatment had a slightly, but significantly, higher prevalence of current back pain than nonusers (48% vs. 42%, respectively, P < 0.05), which could not be explained by differences in occupation, smoking habits, or current physical activity. Although the association be-tween hormone replacement therapy and back problems is weak and probably of minor clinical importance, it is speculated that hormonal effects on joints and ligaments may be involved.

Objective: To identify the long-term risk for low back pain among women with previous severe low back pain during pregnancy.

Methods: In a previous prospective study, 79 pregnant women developed low back pain severe enough to require sick leave. Twelve years later a questionnaire was sent to 62 of these women and 84 controls who did not develop severe low back pain during pregnancy. The questionnaire asked about occupation, low back pain in general and during later pregnancies, and sick leave due to low back pain. There were also questions regarding use of oral contraceptives and its possible relation to low back pain.

Results: The response rate was 84% in the back pain group and 80% among controls. The two groups were similar according to the percentage of women having had another pregnancy (33 of 52 [63%] versus 39 of 67 [58%]) but ten (19%) of the women with previous low back pain stated they had refrained from another pregnancy because of their fear of low back pain compared with only one control. Almost all women (31 of 33) with previous severe low back pain experienced the same symptoms in a subsequent pregnancy, compared with 17 of 39 (44%) controls. Even when they were not pregnant, women with previous low back pain suffered more often and used more sick leave due to low back pain (44 of 52 versus 43 of 67, chi(2) = 5.68, P < .05). The location (sacroiliac joint or lumbar affection) of the previous low back pain did not affect the long-term prognosis. In a logistic regression model, previous low back pain during pregnancy was the only independent risk factor for low back pain during a subsequent pregnancy, whereas an occupation involving physical demand did not affect the results. However, together with previous low back pain during pregnancy, heavy occupation increased the risk for current nonpregnant low back pain.

Conclusion: Women with severe low back pain during pregnancy have an extremely high risk for experiencing a new episode of severe low back pain during another pregnancy and when not pregnant.

Female sex hormones have been suggested to affect the risk of low back pain. One reason is the fact that back pain is a very common symptom during pregnancy. It also seems to be a more common problem among female than male athletes, e.g. in soccer. Although there are few scientific data supporting a relationship between female sex hormones, use of oral contraceptives and low back pain, many doctors and physiotherapists advise women with low back pain to avoid oral contraceptives. The aim of this study was to evaluate whether low back pain fluctuated during the menstrual cycle and differed between women using and not using oral contraceptives. A questionnaire was sent to 12 female soccer teams; 261 players answered and 50 players (28 with back pain and 22 controls) fulfilled the prospective study. At baseline the players underwent a thorough clinical examination and then filled in a diary concerning menstrual data, back pain, training and matches during one season. A total of 296 menstrual cycles was analysed. No difference in prevalence or severity of back pain was seen between the different phases of the menstrual cycle or between users and non-users of oral contraceptives. Our data do not support the hypothesis that low back pain is influenced by hormonal fluctuations during the menstrual cycle or by use of oral contraceptives.

Background: Exogenous and endogenous female sex steroids may influence the risk of low back pain. The fact that back pain is a very common symptom during pregnancy supports this theory. Back pain is also more common among female than male athletes. Oral contraceptives have been suggested to increase the risk of low back pain.

Objective: To evaluate whether the prevalence of low back pain is higher among oral contraceptive users than non-users and if it differs between women taking part in different sports.

Methods:  A questionnaire was sent to female elite athletes in volleyball (n=205), basketball (n=150), and soccer (n=361) as well as to age-matched controls (n=113). The questionnaire comprised questions about age, constitution, occupation, parity and use of contraceptive method as well as previous and current back pain and possible consequences of the back problems.

Results: The response rate was 85%. Between 42% and 52% of the women in the different groups used oral contraceptives. The groups were similar in most background variables, except that the volleyball and basketball players were taller. The prevalence of current low back pain was between 21% and 34% in the different athlete groups with an average of 30%, whereas only 18% of the controls suffered from low back pain (p<0.01). The prevalence of low back pain within each group, athletes as well as controls, was similar in women who used, and did not use oral contraceptives.

Conclusions: This study does not support the theory that low back pain is affected by the use of oral contraceptives. Instead, constitutional factors and mechanical stress during intense physical activity is probably more important.