American journal of epidemiology
-
Vitamin A deficiency is a major public health problem among preschool-aged children in many developing countries. In Bangladesh, a national nutritional surveillance system was initiated in 1990 to monitor 1) the occurrence of vitamin A deficiency by history of night blindness and 2) the routine coverage of national twice-yearly prophylactic vitamin A capsule (VAC) distribution. This study comprised data collected from June 1990 to August 1994. ⋯ Night blindness was inversely related to the level of routinely attained coverage, and the degree of protection was associated with the time interval between the moment of VAC receipt and the moment of data collection. Although the prevalence of vitamin A deficiency in Bangladesh has been considerably lower in the 1990s than it was in the 1980s, it is still prevalent at all socioeconomic levels. Supplementation with high-dose VACs is an effective strategy for reducing night blindness, but the efficiency of the program will improve when coverage in the rural areas increases.
-
The effects of marital status and change in marital status on mortality among middle-aged British men were examined in a prospective cohort study, the British Regional Heart Study. This is a nationally representative cohort of men selected at random from general medical practices in 24 towns in England, Wales, and Scotland. It comprises 7,735 men aged 40-59 recruited in 1978-1980 and followed up for 11.5 years. ⋯ It is unlikely that selection bias, chance, or artifact is responsible for the general relation between marital status and mortality. Variable and incomplete control for confounding by socioeconomic status and risk factors for common diseases may explain some of the inconsistencies observed between studies and between different categories of unmarried men (i.e., never-married, widowed, and divorced). It is possible that the social support offered by marriage exerts a protective effect for some men.
-
Although 40% of US women indicate they are currently trying to lose weight, the association between intentional weight loss and longevity is unknown. The authors analyzed prospective data from 43,457 overweight, never-smoking US white women aged 40-64 years who in 1959-1960 completed a questionnaire that included questions on weight change direction, amount, time interval, and intentionality. Vital status was determined in 1972. ⋯ In women with no preexisting illness (n = 28,388), intentional weight loss of > or = 20 lb (> or = 9.1 kg) that occurred within the previous year was associated with about a 25% reduction in all-cause, cardiovascular, and cancer mortality; however, loss of < 20 lb (< 9.1 kg) or loss that occurred over an interval of > or = 1 year was generally associated with small to modest increases in mortality. The association between intentional weight loss and longevity in middle-aged overweight women appears to depend on their health status. Intentional weight loss among women with obesity-related conditions is generally associated with decreased premature mortality, whereas among women with no preexisting illness, the association is equivocal.
-
In a search for clues to the origin of squamous cell skin cancer (SCC), the authors investigated the pattern of new cancers in a cohort of 5,100 SCC patients whose tumors were diagnosed during the years 1978-1989 and recorded in the Danish Cancer Registry. Subsequent cancer experiences in SCC patients were compared with the cancer incidence in the Danish population using ratios of observed cancers to expected cancers as a measure of the relative risk. Overall, patients with SCC were at increased risk of new malignancies (relative risk (RR) = 1.6, 95% confidence interval (CI) 1.5-1.7). ⋯ A previously undocumented significant excess of smoking-related cancers was observed after an SCC diagnosis, suggesting that smoking may be involved in the development of SCC. Since a variety of other squamous cell cancers have already been linked to smoking, the authors speculate that some general effect of smoking might act on all human squamous epithelia. The observed significant associations with lymphoma and leukemia and the high risk of subsequent malignancies in young SCC patients merit further attention.
-
Increased risk of prostate cancer in men with a family history of the disease has been observed consistently in epidemiologic studies. However, most studies have been confined to white men; little is known about familial aggregation of prostate cancer in populations with unusually high incidence, such as African Americans, or in populations with low incidence, such as Asian-Americans. The authors report results from a population-based case-control study of prostate cancer among blacks, whites, and Asian-Americans in the United States and Canada. ⋯ Sera from 1,087 controls were used to examine the relations between family history and serum concentrations of androgens and prostate-specific antigen. The concentrations of sex hormone-binding globulin were slightly higher in men with than without a positive family history. Prostate-specific antigen concentrations were unrelated to family history.