Mette Lena Olsen

Hip fracture risk in statin users--a population-based Danish case-control study

Based on animal studies, statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) have been suggested as potential agents in the treatment of osteoporosis. In some epidemiological studies, statins have been associated with a reduced fracture risk. Our objective was to examine associations between statin treatment and risk of hip fracture in a population-based case-control study. A total of 6660 subjects with hip fracture and 33,274 gender- and age-matched population controls were identified from 1 January 1994 to 31 December 2001 using the Hospital Patient Register in North Jutland County, Denmark, and the Danish Central Personal Registry, respectively. Data on redeemed prescriptions for statins within the last 5 years before the index date were retrieved from a population-based prescription database. We used conditional logistic regression to estimate odds ratios (OR) for hip fracture according to use of statin prescriptions adjusted for potential confounding factors, i.e. gender, other diseases, and use of other drugs known to affect bone metabolism and fracture risk. After adjustment for potential confounders, statin treatment was associated with a reduced risk of hip fracture (OR=0.68; 95% confidence interval: 0.50–0.93) for those who had redeemed more than three prescriptions for a statin drug. We found that risk of hip fracture decreased with the number of statin prescriptions. Stratified analyses on gender and age did not reveal any major differences between men and women or among different age groups on the estimates between use of statins and hip fracture risk. Our findings support an association between statin treatment and a reduced hip fracture risk. However, it is unclear whether this association is causal.

Risk and short-term prognosis of myocardial infarction among users of antidiabetic drugs.

Old sulphonylureas have been linked with adverse cardiovascular effects; however, data on the clinical implications are sparse. We examined the association between use of sulphonylureas and other antidiabetic drugs and the risk and case fatality rate (CFR) of myocardial infarction (MI) in a population-based case–control and follow-up study, respectively. A total of 6738 cases of first-time MI and 67,374 age- and gender-matched population controls were identified from the Hospital Discharge Registry and the Civil Registration System of North Jutland County, Denmark, in the period 1994 through 2002. Prescriptions for antidiabetic drugs before the index date were retrieved from a prescription database. We estimated odds ratios (ORs) of MI (case–control study) and 30-day CFR (follow-up study) associated with antidiabetic drug use adjusted for possible confounding factors and using nondiabetic subjects as the reference group. The risk of MI appeared higher among users of old sulphonylureas (adjusted OR, 2.07; 95% confidence interval (CI), 1.81–2.37) than among users of new sulphonylureas (adjusted OR, 1.36; 95% CI, 1.01–1.84). The adjusted ORs among users of nonsulphonylurea oral antidiabetic drugs, insulin, and patients with diabetes not receiving pharmacotherapy were 1.38 (95% CI, 0.90–2.11), 2.56 (95% CI, 2.16–3.03), and 3.51 (95% CI, 2.92–4.22), respectively. The overall 30-day CFR was 24.6%, but varied between 9.5% and 37.0% among the different categories. New sulphonylureas may be associated with a lower risk of MI than old sulphonylureas. Furthermore, the 30-day CFR may vary according to type of antidiabetic drug. These differences indicate the need for further examination of the cardiovascular safety of antidiabetic drugs.

Birth weight and risk of early-onset breast cancer (Denmark)

Objective: To investigate if birth weight is associated with early-onset breast cancer. The mechanism behind an association with high birth weight could be the link between fetal growth and estrogens in utero. Methods: We conducted a population-based case–control study in Denmark including 881 women with breast cancer diagnosed before the age of 40 years and 3423 age-matched controls. Information concerning birth weight and other birth-related variables was obtained from midwife reports. Results: The risk of early-onset breast cancer was increased 1.25 times (95% CI 1.00–2.51) for birth weights above 4000 g and 1.59 times (95% CI 1.00–1.55) for birth weights below 2500 g in comparison with birthweights of 3000–3499 g. Conclusions: The finding that high birth weight is associated with breast cancer is compatible with the hypothesis that level of estrogen during pregnancy is related to breast cancer in early adult life. The finding that low birth weight is also associated with breast cancer may indicate that other characteristics of the fetal environment may be important for breast cancer in early adult life.

Corticosteroid use and risk of hip fracture: a population-based case–control study in Denmark

Vestergaard P, Olsen ML, Paaske Johnsen S, Rejnmark L, Toft Sørensen H, Mosekilde L (Aarhus University Hospital, Denmark; and Aarhus and Aalborg University Hospitals; Aarhus, Denmark). Corticosteroid use and risk of hip fracture: a population‐based case–control study in Denmark. J Intern Med 2003; 254: 486–493.

Antipsychotics and risk of first- time hospitalization for myocardial infarction : a population- based case- control study

Background.  Use of antipsychotics has been linked with an adverse cardiovascular risk factor profile and an increased risk of dysrhythmia and sudden cardiac death. However, detailed data on the association between use of antipsychotics and development of atherosclerotic disease are limited.

The intrauterine origin of male breast cancer: a birth order study in Denmark.

First pregnancies are known to have higher oestrogen levels than later ones and first-born women are at increased breast cancer risk compared with later-born women. We hypothesized that a birth order effect might be even more evident in male breast cancer patients, in whom oestrogens in adult life are generally low. In a population-based study in Denmark involving 77 male breast cancer patients and 288 population controls, first-born men compared with later-born men had a relative risk of 1.71 for the disease (95% confidence interval (CI) 1.00–2.92). This result is in line with that seen in female breast cancer cases and indicates that male breast cancer may have roots in the intrauterine life, oestrogens being a likely mediator.

Variation in the classification of polyneuropathies among European physicians

OBJECTIVE Considerable debate still exists regarding the classification of polyneuropathies (PNPs) into predominantly demyelinating, predominantly axonal loss, mixed or unclassified. This study was designed to determine the variation among physicians in the classification of PNPs by using the European Standardized Telematic tool to Evaluate Electromyography knowledge-based systems and Methods (ESTEEM) multicenter database. METHODS Seven physicians from 6 laboratories in Europe sent a total of 156 prospectively collected cases of PNP with electromyography (EMG) data including diagnosis (examination diagnosis) to the database. Each physician interpreted the electrophysiological data from all cases (interpretation diagnosis) and a final diagnosis was given at the consensus meetings of the group (consensus diagnosis). RESULTS Comparison of each physicians examination diagnosis with his/her interpretation diagnosis, i.e. intra-physician variation, showed a change towards less classified PNPs (P < 0.05). Interpretation diagnoses showed large inter-physician variation in the classification of PNPs. The consensus group was more cautious than individual physicians in classifying PNPs as mixed and axonal. The probability of the consensus diagnosis increased with increasing number of abnormal motor and sensory segments tested. CONCLUSIONS Recognition of variation in classification of PNP as shown in this study and suggesting standards of good clinical practice developed by a consensus group may increase the quality of EMG practice.

A REGISTRY-BASED STUDY OF GENDER, FETAL GROWTH, AND RISK OF WILMS TUMOR

The possibility of an interaction between gender and fetal growth on the risk of Wilms tumor is poorly examined. Using nationwide population-based registries, the authors identified all children (= 126) diagnosed with Wilms tumor in Denmark, 1973–1993, and selected 10 matched population controls per case. Data on birth weight, gestational age, and ponderal index were used to examine the association between gender, fetal growth, and risk of Wilms tumor. It was found that the risk of Wilms tumor increased with fetal growth in girls, but decreased with fetal growth in boys, although the findings did not reach statistical significance.