Christer Hogstedt

Sports and osteoarthrosis of the hip An epidemiologic study

To investigate if participation in sports increases the risk of developing osteoarthrosis of the hip, we did a case-control study on the sports activities of 233 men (up to age 49) who were recent recipients of a prosthe sis because of severe idiopathic osteoarthrosis of the hip and 302 men randomly selected from the general population. Assessments of sports, job history, and health status were made by an interview. Men with high exposure to sports of all kinds com bined (in hours) had a relative risk to develop osteoar throsis of the hip of 4.5 compared to those with low exposure. Track and field sports and racket sports seemed to be the most hazardous to the hip joint. Men who had been exposed to high physical loads both from their occupation and sports had a relative risk of 8.5 to develop osteoarthrosis of the hip compared to those with low physical load in both activities. Potential confounding factors, such as age, body mass index, and smoking, were considered. Long-term exposure to sports among men seems to be a risk factor for developing severe osteoarthrosis of the hip; this is increased when combined with heavy load from occupation.

Osteoarthrosis of the knee in men and women in association with overweight, smoking, and hormone therapy

OBJECTIVES The aim was to examine the relation between osteoarthrosis of the knee leading to prosthetic surgery among men and women and overweight, smoking, and hormone therapy. METHODS A case-referent study was performed with a study base of all men and women, born 1921–1938, living in 14 counties in Sweden during 1991–95. The cases (n=625) were identified through the Swedish Knee Arthroplasty Register. The referents (n=548) were randomly selected through the central population register from the same counties. Detailed information on general health status, height, weight, smoking habits, medication, use of hormones, specific physical loads from occupation and housework, and sports activities was collected by a telephone interview and a postal questionnaire. The cases were classified in terms of high, medium or low/non-exposure to the factors studied, according to the distribution of variables among the referents. RESULTS Women with high body mass index (BMI) at the age of 40 had a relative risk of 9.2 (95%CI 5.3, 16.0) of developing severe knee osteoarthrosis later in life, and for men at the same age the relative risk was 3.9 (95%CI 2.3, 6.4). Smokers were less likely to develop severe knee osteoarthrosis compared with non-smokers. Oestrogen therapy for women over 50 showed an increased relative risk of 1.8 (95%CI 1.2, 2.6), while use of oral contraceptives did not influence the risk . CONCLUSION Overweight is a risk factor for knee osteoarthrosis leading to prosthetic surgery in men and women, with the strongest relation for women. Oestrogen therapy after 50 increased the relative risk, while smoking decreased it.

Increased risk of esophageal cancer among workers exposed to combustion products.

Alcohol and tobacco habits have been identified as strong risk factors for esophageal cancer. Increased risks of esophageal cancer have also been reported to be associated with occupational exposure to asbestos and various metals, among vulcanization workers, asphalt workers, and workers in the petrochemical industry. Mortality and cancer incidence were investigated in a series of studies of workers exposed to combustion by-products, i.e., chimney sweeps, waste incinerator workers, gas workers, and bus garage workers exposed to diesel exhausts. The SMRs for esophageal cancer ranged from 150-386 in these cohorts, and a combined SMR of 289 (95% C.I. 174-452) was obtained. Available data on smoking habits and indirect indicators of alcohol consumption show that the excess cannot be attributed solely to these factors. It seems likely that occupational exposure to combustion products is associated with an increased risk of esophageal cancer.

Physical work load in physical education teachers

The main objective was to measure and quantify exposure to physical work load in physical education teachers. A further aim was to establish the reproducibility of a three-week test-retest interval of self-reported physical load and to evaluate the agreement between registered and self-rated physical load. Thirty teachers, both female and male, volunteered to participate in the study. The physical load on the lower extremities, as well as the back and the cardio-vascular strain was recorded during one working day. The results indicate that the physical work load in this occupational group is considerable due to the load on the lower extremities. The demands of the cardio-vascular system are also relatively high in comparison to other occupational groups. The teachers could assess their activity quite well regarding heavy lifting and time spent sitting.