A.L.M. Verbeek

BACKGROUND: Most knowledge on chronic fatigue (CF) and chronic fatigue syndrome (CFS) is based on clinical studies, not representative of the general population. This study aimed to assess the prevalence of fatigue in an adult general population and to identify associations with lifestyle factors. METHODS: Total 22,500 residents of Nijmegen were selected at random and interviewed by questionnaire. Data on 9062 respondents (43% response) were analysed, taken into account age, gender and concomitant disease. Subjects were classified into four groups: not fatigued (NF, reference group), short-term fatigue (SF, <6 months), chronic fatigue (CF, >or=6 months) and CFS-like fatigue (in accordance with the Center for Disease Control criteria for CFS, without clinical confirmation). RESULTS: Our study population showed the following breakdown: NF 64.4% (95% CI 63.6-65.6%), SF 4.9% (95% CI 4.5-5.4%), CF 30.5% (95% CI 29.5-31.4%) and CFS-like fatigue 1.0% (95% CI 0.8-1.2%). Compared with the NF group, more of the CFS respondents were female [odds ratio (OR) = 1.9], obese (OR = 4.1), using analgesics (OR = 7.8), had a low alcohol intake (OR = 0.4), were eating less healthy food (OR = 0.5) and were physically less active (OR = 0.1). These associations largely applied to the SF and CF group. The fatigue could have been due to a concomitant disease in 34 and 55.5% of the SF and CF cases, respectively. CONCLUSION: The prevalence of CF in the general population appears to be much higher than previously indicated. Even with strict criteria for CFS, it is estimated that approximately 1% of the adult population experiences this condition. Interestingly, a large part of this group remains unrecognized by the general practitioner. A striking similarity in lifestyle pattern between SF, CF and CFS calls for further research.

The effect of the implementation of the Dutch breast cancer screening programme during 1990-1997 on the incidence rates of breast cancer, particularly advanced breast cancer, was analysed according to stage at diagnosis in seven regions, where no screening took place before 1990. The Netherlands Cancer Registry provided detailed data on breast cancer incidence in 1989-1997 by tumour stage, age and region. Annual age-adjusted incidence rates of all breast cancers and advanced cancers, defined as large tumours T2+ with lymph node and/or distant metastases, were compared with rates in 1989. In general, breast cancer incidence rose strongly in the early 1990s, especially in the age category 50-69 years (estimated annual percentage change (EAPC) 4.25; 95% CI 1.70, 6.86). The increase was mainly due to the increase in small T1 cancers and ductal carcinoma in situ. However, in women aged 50-69, advanced cancer incidence rates showed a significant decline by 12.1% in 1997 compared with 1989 (EAPC -2.14, 95% CI -3.47, -0.80), followed by a breast cancer mortality reduction of similar size after approximately 2 years. We confirm that breast cancer screening initially leads to a temporary strong increase in the breast cancer incidence, which is followed by a significant decrease in advanced diseases in the women invited for screening. It is evident that breast cancer screening contributes to a reduction in advanced breast cancers and breast cancer mortality.

PURPOSE: Experimental and epidemiological studies suggest that low antioxidant intake may be associated with the occurrence of neovascular age-related macular degeneration (AMD). METHODS: We investigated this hypothesis further with a case-control study involving 72 case and 66 control patients attending the Ophthalmology Department of the University Hospital in Nijmegen. Data were collected by interview on antioxidant intake (i.e. in fruit and vegetables), cigarette smoking, sunlight exposure and familial predisposition. Antioxidant intake was calculated according to the method described in the Framingham Eye Study. Logistic regression analysis was used to estimate odds ratios (OR) and 95% confidence intervals (CI). RESULTS: The prevalence rate of AMD in patients with low antioxidant intake and low lutein intake (dichotomized at the median value) was about twice as high as that in patients with high intake: OR = 1.7, 95% CI (0.8-3.7), and OR = 2.4, 95% CI (1.1-5.1). Further specification of intake data into quartiles of antioxidant intake and lutein/zeaxanthine intake showed a clear dose-response relationship. CONCLUSION: The effect of dietary antioxidants upon macular health warrants preventive studies.