AN EARLIER FRACTURE AS A RISK FACTOR FOR NEW FRACTURE AND ITS ASSOCIATION WITH SMOKING AND MENOPAUSAL AGE IN WOMEN

Objectives: The purpose of this study was to investigate whether a pre vious fracture is a risk factor for fracture later in life and its ass ociation with tobacco smoking, menopausal age and the use of oral cont raceptives. This is an epidemiological population study based on a que stionnaire. A sample of 10 000 women from seven birth cohorts between 1900-1940 was obtained at random from the population register. The ove rall response rate was 74.6%. The responders (n = 7459) represented 53 % of the total population. Methods: The women from all these birth coh orts were questioned regarding a possible history of fractures and the year in which they were sustained. The questionnaire also included qu estions about menopausal age, use of oral contraceptives, previous gyn aecological operations and possible oestrogen medication. The women fr om the 1900-1920 birth cohorts were questioned in detail about urogeni tal disorders, while tobacco smoking data were recorded only for the 1 930 and 1940 birth cohorts. Results: The relative risk of sustaining a further fracture was significantly related to fracture premenopausall y before 40 years of age and later fracture postmenopausally after 60 years of age (1.29; 0.97-1.70) compared to controls (0.78; 0.59-1.03)( P = 0.03). Both an early menopause and tobacco smoking were associated significantly with repeated fractures, while use of oral contraceptiv es had a protective effect against repeated fractures in the 1940 birt h cohort. Logistic multiple regression showed that a fracture was a si gnificant independent risk factor for further fracture in both cohorts 1900-1920 (P < 0.01) and 1930-1940 (P < 0.05). Conclusions: This stud y suggests poorer protective resources against new fractures among wom en with previous fractures, and that lack of oestrogen menopausally ca n partly explain the enhanced risk of fracture, not only during the me nopause but also later in life when a hip fracture may have immense co nsequences. The results should draw our attention to emphasise the nee d for active treatment of patients with established osteoporosis becau se of the increased risk of new fractures later in life.