We sought to determine the incidence rate of carpal tunnel syndrome in the general population. Using three different case definitions, we conducted a prospective study to ascertain by medical record review all cases of incident disease in a defined population during a 2-year period. Newly diagnosed probable or definite carpal tunnel syndrome (N = 309) occurred at a rate of 3.46 cases per 1,000 person-years (95% confidence interval = 3.07-3.84). The incidence rate in our study was 3.5 times higher than the rate 20 years ago in a Minnesota city. The rate difference probably results from a combination of reasons, including a true rise in incidence.

Objective-To determine the individual, physical, and psychosocial risk factors for carpal tunnel syndrome in a general population.Methods-Population based case-control study in Marshfield epidemiological study area in Wisconsin, USA. Cases were men and women aged 18-69 with newly diagnosed carpal tunnel syndrome (n=206 (83.1%) of 248 eligible). Controls were a random sample of residents of the study area who had no history of diagnosed carpal tunnel syndrome (n=211 (81.5%) of 259 eligible). Cases and controls were matched by age. Telephone interviews and reviews of medical records obtained height and weight, medical history, average daily hours of exposure to selected physical and organisational work factors, and self ratings on psychosocial work scales.Results-In the final logistic regression model, five work and three non-work variables were associated with risk of carpal tunnel syndrome, after adjusting for age. For each one unit of increase in body mass index (kg/m(2)), risk increased 8% (odds ratio (OR) 1.08; 95% confidence interval (95% CI) 1.03 to 1.14). Having a previous musculoskeletal condition was positively associated with carpal tunnel syndrome (OR 2.54; 95% CI 1.03 to 6.23). People reporting the least influence at work had 2.86 times the risk (95% CI, 1.10 to 7.14) than those with the most influence at work.Conclusions-Carpal tunnel syndrome is a work related disease, although some important measures of occupational exposure, including keyboard use, were not risk factors in this general population study. The mechanism whereby a weight gain of about six pounds increases the risk of disease 8% requires explanation.

To capitalize on Marshfield Clinic's advantages for population-based health research, we developed the Marshfield Epidemiologic Study Area (MESA). Marshfield Clinic is an integrated system consisting of a large multispecialty clinic and 23 affiliated clinics. Clinic physicians provide virtually all of the medical care, both inpatient and outpatient, for residents of the area. MESA consists of 14 ZIP codes in which over 95% of the 50,000 residents and most significant health events are captured in Marshfield Clinic databases, including all deaths, 94% of hospital discharges, and 92% of medical outpatient visits. MESA exemplifies the research potential of integrated medical care systems and the efforts required to realize that potential, Because it is representative of a defined population and provides an unselected sample of patients, MESA is well suited for epidemiologic research and research elucidating the clinical spectrum and natural history of diseases and the effectiveness of treatment.

Objective.-To investigate recent trends in the percentage and characteristics of patients being treated by a physician for high blood cholesterol (HBC) and to assess missed clinical opportunities to screen for HBC.Design, Setting, Participants.-Telephone interviews of 154 735 adults in 37 states that participated in the Behavioral Risk Factor Surveillance System during 1988-1990 to assess trends in the percentage of patients treated for HBC by a physician. An opportunity was considered missed if a person did not report being screened for HBC despite seeing a physician for preventive care in the last 2 years.Results.-Between the first quarter of 1988 and the last quarter of 1990, the percentage of persons treated by a physician for HBC increased from 7.6% to 11.7% (P<.001). However, since an estimated 36% of US adults need treatment for HBC, fewer than one third of persons who need treatment are receiving it. Persons with two or more cardiac risk factors were more likely to be treated, while men, blacks, persons in lower socioeconomic groups, and persons between 20 and 34 years of age were less likely to be treated. Among the 126 571 persons who had seen a physician for preventive care within the last 2 years, missed opportunities to screen for HBC were most common among persons aged 20 through 34 years (59%) and among women who had seen obstetricians/gynecologists for preventive care (43%).Conclusions.-Fewer than one third of persons who need treatment for HBC as estimated by data from the second National Health and Nutrition and Nutrition Examination Survey are receiving treatment. Better use of clinical opportunities to screen for HBC could substantially accelerate the progress in identifying persons, young adults in particular, who are likely to benefit from cholesterol reduction.

OBJECTIVE:To investigate a reported association between dental disease and risk of coronary heart disease.SETTING:National sample of American adults who participated in a health examination survey in the early 1970s.DESIGN:Prospective cohort study in which participants underwent a standard dental examination at baseline and were followed up to 1987. Proportional hazards analysis was used to estimate relative risks adjusted for several covariates.MAIN OUTCOME MEASURES:Incidence of mortality or admission to hospital because of coronary heart disease; total mortality.RESULTS:Among all 9760 subjects included in the analysis those with periodontitis had a 25% increased risk of coronary heart disease relative to those with minimal periodontal disease. Poor oral hygiene, determined by the extent of dental debris and calculus, was also associated with an increased incidence of coronary heart disease. In men younger than 50 years at baseline periodontal disease was a stronger risk factor for coronary heart disease; men with periodontitis had a relative risk of 1.72. Both periodontal disease and poor oral hygiene showed stronger associations with total mortality than with coronary heart disease.CONCLUSION:Dental disease is associated with an increased risk of coronary heart disease, particularly in young men. Whether this is a causal association is unclear. Dental health may be a more general indicator of personal hygiene and possibly health care practices.

BACKGROUND:Although coronary heart disease mortality has been decreasing, little is known about trends in morbidity from coronary heart disease. We evaluated trends in nonfatal coronary heart disease in the United States during 1980 through 1989.METHODS:We analyzed data from the National Health Interview Survey, an ongoing survey of representative samples of the civilian, noninstitutionalized population of the United States. Survey respondents were determined to have coronary heart disease if they reported ever having a myocardial infarction or heart attack, angina pectoris, or coronary heart disease. Incidence was defined as initial onset of a coronary heart disease condition during the year preceding the interview date.RESULTS:About 6 million people were estimated to be living with coronary heart disease. The age-standardized prevalence was relatively constant at about 25 per 1000. Among white men, however, prevalence increased significantly over the 10-year period. Among 75- to 84-year-old men, prevalence increased from 100 per 1000 in 1980 to 179 per 1000 in 1989. Among men and women 45 to 54 years old, prevalence decreased. Overall, the incidence rate of nonfatal coronary heart disease was relatively flat (at about 3 per 1000 per year after 1983). Among white women, the incidence rate increased from 1.4 to 2.8 per 1000, and by the end of the decade it nearly equaled the incidence rate among white men.CONCLUSIONS:Overall, the burden of nonfatal coronary heart disease remained fairly constant during the 1980s. The trends, however, were not uniform in all population groups. The apparent increasing incidence among women deserves continued monitoring. An encouraging trend is the decreasing prevalence in the younger age groups.

To estimate the association between the immunologic responses of the cell-mediated and humoral systems and alcohol drinking, we used data from the Vietnam Experience Study conducted by the Centers for Disease Control. That study, conducted from 1985 to 1986, was based on a random sample of 4462 male, Vietnam-era, U.S. veterans. By using linear regression, we evaluated how (1) the number of alcoholic drinks the subjects consumed per month and (2) the drinking cessation of certain subjects were associated with their relative and absolute T, B, CD4, and CD8 lymphocyte counts and immunoglobulin A (IgA), IgM, and IgG levels. We used geometric means and percentage differences in geometric means of immune status to measure the associations and adjusted these values to account for the effect of covariates. The results indicated that measures of immune status differed among the drinking categories and that, generally, the differences changed after adjustment for covariates. These differences consisted, as alcohol consumption increased, of higher IgA and IgM levels, relative T and CD4 lymphocytes, and the ratio of CD4 to CD8 cells, and of lower IgG levels, relative B and CD8 lymphocytes, absolute lymphocyte, and lymphocyte subset counts after adjusting for other covariates. Among former drinkers, we found no clear-cut pattern in measures of immunity for a few years after cessation and then found that values of former drinkers tended to return toward values of nondrinkers as they continued to abstain.

We investigated the relation between various sperm characteristics, including morphometric parameters, and impaired fertility among 596 men who participated in a national study. Semen was collected and processed by using a standardized protocol, and sperm measurements were made using a computer-aided sperm analysis instrument. We defined infertility in two ways: (1) the inability to father a child after trying for a year or longer, and (2) the number of children fathered. We found that all measures of sperm motion were decreased among men with impaired fertility. After adjustment for the other motion parameters and various potential confounders, however, only the percentage of progressive cells was associated with infertility. One morphometric parameter, the mean length/width ratio, was consistently associated with both measures of infertility, even after adjustment for potential covariates. This measure was also strongly associated with infertility among various subgroups defined by poor sperm concentration, motility, and morphology. The sperm length/width ratio appears to be an important correlate of infertility in males.

Although levels of high density lipoprotein (HDL) cholesterol in males decrease during adolescence and after treatment with testosterone derivatives, several studies have reported that levels of HDL cholesterol are positively associated with endogenous levels of testosterone in men. This association was further examined using data collected during 1985 and 1986 from 3,562 white and 500 black men who ranged in age from 31 to 45 years. Black men had higher mean levels of both HDL cholesterol (8 mg/dl) and total testosterone (33 ng/dl) than white men, and positive associations were observed between testosterone and HDL cholesterol levels (r = 0.22, whites; r = 0.26, blacks). In addition, levels of testosterone were related positively to alcohol consumption and cigarette smoking and negatively to age, Quetelet index, and use of beta-blockers. We used stratification and regression analyses to determine if any of these characteristics could account for the positive association between levels of HDL cholesterol and total testosterone. Although controlling for most factors had little influence, adjusting for Quetelet index reduced the strength of the association between levels of testosterone and HDL cholesterol by approximately 30%. These findings suggest that the positive association between levels of testosterone and HDL cholesterol may not be causal. Multivariable analyses that control for obesity and other potentially confounding characteristics should be used in studies that assess the relation of testosterone levels to coronary heart disease.

Although coronary heart disease is a leading cause of morbidity and mortality among persons with diabetes, the risk factors for coronary heart disease have not been well established for this population. The authors performed a case-control analysis by using data from two large population-based surveys. Cases of persons who died of coronary heart disease were identified from the 1986 National Mortality Followback Survey, and controls were taken from behavioral risk factor surveys conducted in 35 states in 1988. Diabetic women younger than 55 years with no other risk factors for coronary heart disease had a 16-fold higher risk of dying from coronary heart disease than did women without diabetes. About one-third of younger women who died of coronary heart disease had diabetes. Diabetic men less than 45 years old with no other risk factors for coronary heart disease had an eightfold higher risk of coronary heart disease mortality. Among older white men and women, diabetes increased the risk of mortality from coronary heart disease about twofold. In younger diabetics, current cigarette smoking was associated with a 50% increase in risk, and high blood pressure increased the risk more than threefold. In the older age group, risk factors for coronary heart disease mortality were similar among those with and those without diabetes: Cigarette smoking and high blood pressure each were associated with about a twofold increase in risk. Diabetes is a particularly strong risk factor for mortality from coronary heart disease in young adults. Smoking and blood pressure control represent major opportunities to reduce the risk of coronary heart disease among persons with diabetes.

Although socioeconomic status has been positively related to levels of high density lipoprotein (HDL) cholesterol in white Americans, limited evidence suggests that an inverse association may exist among blacks. These associations were further examined using data collected in 1985-1986 from 3,562 white and 500 black men who ranged in age from 31 to 45 years. Overall, mean levels of HDL cholesterol were 8 mg/dl higher among blacks than among whites and, in each group, levels were related positively to alcohol consumption and negatively to Quetelet index and cigarette smoking. A statistically significant interaction, however, was observed between race and educational achievement: no association was seen between educational achievement and levels of HDL cholesterol among white men, but there was an inverse association among blacks. For example, a 13 mg/dl (55 vs. 42 mg/dl) difference in levels of HDL cholesterol was observed between black and white men who did not complete high school, but only a 3 mg/dl black excess (47 vs. 44 mg/dl) was seen among college graduates. About 40 percent of this reduction could be attributed to the effects of cigarette smoking, alcohol consumption, and relative weight. These results indicate that the higher levels of HDL cholesterol frequently found among black men in the United States may not apply to all social strata. Other characteristics, such as physical activity and diet, may account for the differing race-specific associations with educational achievement.

As part of an epidemiologic study of the health status of a randomly selected group of Vietnam veterans, we measured the semen characteristics of 324 Vietnam veterans and compared them with a similar group of 247 veterans who did not serve in Vietnam. The participation rate was 81% in both groups. Measurements of sperm concentration, movement characteristics, and head dimensions were performed, using the Cellsoft computer-assisted semen analysis system. We found that Vietnam veterans had significantly (p less than 0.05) lowered mean sperm concentrations (64.8 x 10(6) sperm/mL for Vietnam veterans vs 79.8 x 10(6) sperm/mL for non-Vietnam veterans), and Vietnam veterans were twice as likely to have sperm concentrations less than or equal to 20 million/mL (odds ratio = 2.7, 95% confidence interval = 1.3-5.7). Vietnam veterans also had a significantly lowered mean proportion of morphologically normal sperm heads (57.9% vs 60.8%), with significantly longer mean major axis length and head circumference. The proportion of motile cells, velocity, linearity, amplitude of lateral head displacement, and beat frequency were not different between the two groups. Despite differences in sperm characteristics, Vietnam and non-Vietnam veterans reported fathering similar numbers of children.

We analyzed data from the Walnut Creek Contraceptive Drug Study to compare the menstrual characteristics of 719 women who had tubal sterilizations and 1083 women whose partners had undergone a vasectomy. Study participants were enrolled from 1968 to 1972 and followed up through 1976. The tubal sterilization group had slightly increased, though in most instances not statistically significant, risks of moderate to severe menstrual cramps and adverse menstrual bleeding. At follow-up intervals longer than 2 years, the tubal sterilization group had significantly increased risks of abnormal menstrual cycles and combinations of two or more adverse menstrual outcomes. Tubal sterilization was not associated with an increased risk of premenstrual symptoms. These findings suggest that the types of tubal sterilization procedures which were performed during the early 1970s possibly carry some increased risk of menstrual disturbances, particularly abnormal cycles, and that it may take more than 2 years for the increased risk to become apparent.

Data on the risk of death associated with various contraceptive methods are incomplete. Therefore, we analyzed the mortality rates for young, black inner-city women who used one of four methods of contraception--oral contraceptives, depomedroxyprogesterone acetate, intrauterine (contraceptive) devices, and barrier methods. The subjects were 30,580 15- to 44-year-old women who enrolled at a family planning clinic between 1967 and 1972 and who were observed by monitoring death certificates through the end of 1977. Forty percent of the 218 deaths observed were from accidents and violence. Use of this family planning clinic greatly reduced the risk of death from childbearing; only two deaths were associated with pregnancy and childbirth, compared with the 24 deaths expected. Overall, users of the four methods died at similar, low rates. Given that this study involves considerable loss to follow-up, possible acute effects of contraceptives (eg, infections or thrombosis) are more accurately estimated than possible long-term effects (eg, cancer).