Long or highly irregular menstrual cycles as a marker for risk of type 2 diabetes mellitus.

CONTEXT: Although oligomenorrhea has been associated cross-sectionally with insulin resistance and glucose intolerance, it is not known whether oligomenorrhea is a marker for increased future risk of type 2 diabetes mellitus (DM). OBJECTIVE: To prospectively assess risk of type 2 DM in women with a history of long or highly irregular menstrual cycles. DESIGN AND SETTING: The Nurses' Health Study II, a prospective observational cohort study. PARTICIPANTS: A total of 101 073 women who had no prior history of DM and who reported their usual menstrual cycle pattern at age 18 to 22 years on the baseline (1989) questionnaire. MAIN OUTCOME MEASURE: Incident reports of DM, with follow-up through 1997, compared among women categorized by menstrual cycle length (5 categories). RESULTS: During 564 333 person-years of follow-up, there were 507 cases of type 2 DM. Compared with women with a usual cycle length of 26 to 31 days (referent category) at age 18 to 22 years, the relative risk (RR) of type 2 DM among women with a menstrual cycle length that was 40 days or more or was too irregular to estimate was 2.08 (95% confidence interval [CI], 1.62-2.66), adjusting for body mass index at age 18 years and several other potential confounding variables. The RR of type 2 DM associated with long or highly irregular menstrual cycles was greater in obese women, but was also increased in nonobese women (at body mass indexes at age 18 years of <25, 25-29, and >/=30 kg/m, RRs were 1.67 [95% CI, 1.14-2.45], 1.74 [95% CI, 1.07-2.82], and 3.86 [95% CI, 2.33-6.38], respectively). CONCLUSION: Women with long or highly irregular menstrual cycles have a significantly increased risk for developing type 2 DM that is not completely explained by obesity.     

Alcohol intake in early adulthood and risk of colorectal cancer: three large prospective cohort studies of men and women in the United States

European Journal of Epidemiology - Heavy alcohol consumption in mid-adulthood is an established risk factor of colorectal cancer (CRC). Alcohol use in early adulthood is common, but its association...     

The Role of Radiation Therapy and 5-Fluorouracil in Colon and Rectal Cancer

Since the original report improved survival of patients with locally unresectable gastric cancer treated with irradiation and 5-fluorouacil (5-FU) in 1968, there has been extensive investigation of this treatment combination in a variety of gastrointestinal tumors, including colon and rectal cancer. There are now extensive data supporting the use of 5-FU-based chemotherapy with irradiation in the adjuvant treatment of rectal cancer and increasing experience defining its role in negotiant therapy. The value of adjuvant 5-FU-based chemotherapy and irradiation in colonies cancer is controversial, but there may be subsets of patients who benefit from this treatment. Ongoing studies in rectal and colon cancer are evaluating the role of irradiation with various modes of 5-FU adminstration (bolus v short or continuous infusion) as well as its modulation with other agents.     

Risk factors for basal cell carcinoma of the skin in men: results from the health professionals follow-up study.

The authors examined the relation of constitutional factors and sun exposure to risk of basal cell carcinoma of the skin (BCC) in a prospective cohort of 44,591 predominantly Caucasian US male health professionals, 40-75 years of age and free of cancer at enrollment in 1986. During 8 years of follow-up, 3,273 cases of self-reported BCC were documented. The following variables were each associated with an elevated risk of BCC: having red hair; green, hazel, or blue eyes; a tendency to sunburn; and north European ancestry. The lifetime number of blistering sunburns was also positively associated with BCC risk (p trend < 0.0001). Compared with men who as teenagers had been outside less than once a week, men who had been outside weekly (relative risk (RR) = 1.30; 95% confidence interval (CI): 1.14, 1.47) and daily (RR = 1.42; 95% CI: 1.24, 1.63) had an elevated risk of BCC. Living in a region of residence with high solar radiation as an adult was also associated with an increased risk of BCC (RR = 1.48; 95% CI: 1.36, 1.60), whereas living in such a region only in childhood did not increase BCC risk. These results confirm the role of constitutional factors and suggest that adult sun exposure increases BCC risk.     

Dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease among women

BACKGROUND: Experimental studies in laboratory animals and humans suggest that alpha-linolenic acid (18:3n-3) may reduce the risk of arrhythmia. OBJECTIVE: The objective was to examine the association between dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease (IHD). DESIGN: This was a prospective cohort study. The intake of alpha-linolenic acid was derived from a 116-item food-frequency questionnaire completed in 1984 by 76283 women without previously diagnosed cancer or cardiovascular disease. RESULTS: During 10 y of follow-up, we documented 232 cases of fatal IHD and 597 cases of nonfatal myocardial infarction. After adjustment for age, standard coronary risk factors, and dietary intake of linoleic acid and other nutrients, a higher intake of alpha-linolenic acid was associated with a lower relative risk (RR) of fatal IHD; the RRs from the lowest to highest quintiles were 1.0, 0.99, 0.90, 0.67, and 0.55 (95% CI: 0.32, 0.94; P for trend = 0.01). For nonfatal myocardial infarction there was only a modest, nonsignificant trend toward a reduced risk when extreme quintiles were compared (RR: 0.85; 95% CI: 0.61, 1.19; P for trend = 0.50). A higher intake of oil and vinegar salad dressing, an important source of alpha-linolenic acid, was associated with reduced risk of fatal IHD when women who consumed this food > or =5-6 times/wk were compared with those who rarely consumed this food (RR: 0.46; 95% CI: 0.27, 0.76; P for trend = 0.001). CONCLUSIONS: This study supports the hypothesis that a higher intake of alpha-linolenic acid is protective against fatal IHD. Higher consumption of foods such as oil-based salad dressing that provide polyunsaturated fats, including alpha-linolenic acid, may reduce the risk of fatal IHD.     

Presenting statistical uncertainty in trends and dose-response relations.

When one estimates the effects of a polytomous exposure, it is common practice to express all effects relative to a baseline or reference level. Certain authors have challenged this practice and proposed alternatives, which we review here. One alternative, the "floating absolute risk" method, can supply useful statistics and trend graphs, but it does not yield valid confidence intervals for relative risks. All categorical methods have further shortcomings when the exposure is continuous, however. These shortcomings can be addressed by plotting or tabulating confidence limits for points on a flexible curve fitted to the uncategorized data.     

Efficacy of "high-intensity" blue-light and "standard" daylight phototherapy for non-haemolytic hyperbilirubinaemia

We report our clinical experience with phototherapy in 3802 infants; 3629 were exposed to "standard" daylight phototherapy and 173 to "high-intensity" blue-light phototherapy. High-intensity blue-light phototherapy was twice as effective as standard daylight phototherapy in decreasing bilirubin concentrations. No failures occurred with high-intensity phototherapy compared with an overall failure rate of 1.84/1000 with daylight lamps; these cases were transferred to high-intensity phototherapy with prompt response. Rebound after cessation of phototherapy was greater in those exposed to high-intensity blue light with a significantly greater number requiring a second exposure. However, the incidence was still low. No third exposure was required in any infant. Nursing of infants under high-intensity blue light was more difficult and inconvenient as was clinical monitoring. The light also caused more stress on the nursing and medical personnel. However, the infants tolerated both types of phototherapy equally well. High-intensity blue-light phototherapy would seem to be the treatment of choice for infants with rapidly increasing or very high bilirubin levels, as well as in those not responding adequately to daylight phototherapy.     

Predicting outcome of care in the neonatal intensive care unit

The accuracy of a neonatal intensive care unit (NICU) staff in predicting the outcome and length of stay of infants admitted to the NICU, and the factors they felt were important in making these predictions, were evaluated. This prospective study used a questionnaire to survey 44 nurses, residents, and attending neonatologists working in the NICU about the predicted outcomes of 52 infants admitted to the NICU at the University of Nebraska Medical Center over a 1-month period. Factors previously identified by the staff as important indicators of infant outcome were assigned points of importance by the respondents, and specific values for these factors were recorded for each infant. The NICU staff indicated that gestational age was the most important indicator of infant outcome. The attending neonatologists placed more value on gestational age (analysis of variance [ANOVA] P less than .0001) than did the nurses or residents. Among the staff groups, there were significant differences in the weight or points assigned to a given factor for pulmonary function, renal function, number of resuscitations, and the "other" category (ANOVA P less than .05). The nurses ranked pulmonary function criteria lower than the residents did (P less than .04), but considered renal function more important than either the residents (P = .005) or the attending neonatologists considered it to be (P = .01). The number of resuscitations was ranked higher by the nursing staff than by other groups, whereas the attending neonatologists assigned less importance to the "other" category.(ABSTRACT TRUNCATED AT 250 WORDS)     

Absolute fat mass, percent body fat, and body-fat distribution: which is the real determinant of blood pressure and serum glucose?

Associations of body mass index (BMI), absolute fat mass, percent body fat, and regional fat distribution with concentrations of fasting blood glucose and blood pressure were examined cross-sectionally in 1551 men and women aged 15-79 y from two study centers. Measurements included height, weight, multiple skinfold thicknesses, body density by underwater weighing, and waist and hip girths. Three principal findings emerged: 1) Absolute overall body mass and fat mass were stronger predictors of blood pressure and blood glucose than were relative fat mass, after age, height, and current cigarette-smoking status were adjusted for; 2) when diastolic blood pressure and serum glucose were used as the external validity criteria, densitometry was not a "gold standard" for body composition associated with risk for increased blood pressure and serum glucose; and 3) BMI was as good a predictor of blood pressure and glucose as was any other measure of body fat in nearly all analyses.     

Correction of logistic regression relative risk estimates and confidence intervals for random within-person measurement error.

Frequently, covariates used in a logistic regression are measured with error. The authors previously described the correction of logistic regression relative risk estimates for measurement error in one or more covariates when a "gold standard" is available for exposure assessment. For some exposures (e.g., serum cholesterol), no gold standard exists, and one must assess measurement error via a reproducibility substudy. In this paper, the authors present measurement error methods for logistic regression when there is error (possibly correlated) in one or more covariates and one has data from both a main study and a reproducibility substudy. Confidence intervals from this procedure reflect error in parameter estimates from both studies. These methods are applied to the Framingham Heart Study, where the 10-year incidence of coronary heart disease is related to several coronary risk factors among 1,731 men disease-free at examination 4. Reproducibility data are obtained from the subgroup of 1,346 men seen at examinations 2 and 3. Estimated odds ratios comparing extreme quintiles for risk factors with substantial error were increased after correction for measurement error (serum cholesterol, 2.2 vs. 2.9; serum glucose, 1.3 vs. 1.5; systolic blood pressure, 2.8 vs. 3.8), but were generally decreased or unchanged for risk factors with little or no error (body mass index, 1.6 vs. 1.6; age 65-69 years vs. 35-44 years, 4.3 vs. 3.8; smoking, 1.7 vs. 1.7).