Glycemic index,glycemic load,and risk of type 2 diabetes

The possibility that high, long-term intake of carbohydrates that are rapidly absorbed as glucose may increase the risk of type 2 diabetes has been a long-standing controversy. Two main mechanisms have been hypothesized, one mediated by increases in insulin resistance and the other by pancreatic exhaustion as a result of the increased demand for insulin. During the past decade, several lines of evidence have collectively provided strong support for a relation between such diets and diabetes incidence. In animals and in short-term human studies, a high intake of carbohydrates with a high glycemic index (a relative measure of the incremental glucose response per gram of carbohydrate) produced greater insulin resistance than did the intake of low-glycemic-index carbohydrates. In large prospective epidemiologic studies, both the glycemic index and the glycemic load (the glycemic index multiplied by the amount of carbohydrate) of the overall diet have been associated with a greater risk of type 2 diabetes in both men and women. Conversely, a higher intake of cereal fiber has been consistently associated with lower diabetes risk. In diabetic patients, evidence from medium-term studies suggests that replacing high-glycemic-index carbohydrates with a low-glycemic-index forms will improve glycemic control and, among persons treated with insulin, will reduce hypoglycemic episodes. These dietary changes, which can be made by replacing products made with white flour and potatoes with whole-grain, minimally refined cereal products, have also been associated with a lower risk of cardiovascular disease and can be an appropriate component of recommendations for an overall healthy diet.     

Vitamins and carotenoids intake and the risk of basal cell carcinoma of the skin in women (United States)

Objective: We examined prospectively intakes of vitamins A, C, and E, folate, and specific carotenoids in relation to the risk of basal cell carcinoma of the skin (BCC) in women. Methods: Dietary intake was assessed by food-frequency questionnaires every two–four years and the first diagnosis of BCC was ascertained by self-report every two years. We used logistic regression to model the association between dietary intake and the risk of BCC adjusting for various health, sun exposure, and sun sensitivity factors. Results: During 12 years of follow-up we recorded 5392 cases. We did not find any significant inverse associations between these dietary factors and BCC. On the contrary, weak positive trends were seen with vitamins A, C, and E, and folate. The multivariate relative risks (RRs) comparing the top to bottom quintile were 1.20 (95% CI = 1.10–1.31) for folate, 1.16 (95% CI = 1.06–1.26) for vitamin A, 1.13 (95% CI = 1.03–1.23) for vitamin C, and 1.15 (95% CI = 1.06–1.26) for vitamin E. Exploration of latency periods did not suggest different associations with a particular duration. Conclusions: We did not find evidence that vitamins A, C, and E, and folate, or specific carotenoids play an important protective role against the incidence of BCC.     

Intake of dairy products,calcium, and vitamin d and risk of breast cancer

BACKGROUND: Laboratory data suggest that calcium and vitamin D, found at high levels in dairy products, might reduce breast carcinogenesis. However, epidemiologic studies regarding dairy products and breast cancer have yielded inconsistent results. We examined data from a large, long-term cohort study to evaluate whether high intake of dairy products, calcium, or vitamin D is associated with reduced risk of breast cancer. METHODS: We followed 88 691 women in the Nurses' Health Study cohort from the date of return of their food-frequency questionnaire in 1980 until May 31, 1996. Dietary information was collected in 1980 and updated in 1984, 1986, 1990, and 1994. We identified 3482 women (premenopausal = 827, postmenopausal = 2345, and uncertain menopausal status = 310) with incident invasive breast cancer. We used pooled logistic regression to estimate multivariable relative risks (RRs) using 2-year time increments. The RRs and 95% confidence intervals (CIs) were calculated for each category of intake compared with the lowest intake group. All statistical tests were two-sided. RESULTS: Intakes of dairy products, calcium, or vitamin D were not statistically significantly associated with breast cancer risk in postmenopausal women. In premenopausal women, however, consumption of dairy products, especially of low-fat dairy foods and skim/low-fat milk, was inversely associated with risk of breast cancer. The multivariable RRs comparing highest (>1 serving/day) and lowest (800 mg/day versus 500 IU/day versus 相似文献   

Population-based demographic study of karyotypes in 1709 patients with adult acute myeloid leukemia.

Few large demographic studies of acute myeloid leukemia (AML) are derived from population-based registries. Demographic and karyotypic data were provided for AML cases from two regional leukemia registry databases in Scotland and the Northern Region of England. A population-based dataset was compiled, comprising 1709 patients aged >16 years (1235 North England/474 Scotland patients). The most common cytogenetic abnormalities involved chromosomes 5 and/or 7 (17%). Patients with the following abnormal chromosome 5/7 combinations: -5, del(5q), -5/-7 and del(5q)/-7 represented a significantly older population (P < 0.01, ANOVA). t(8;21) was the only 'favourable' karyotype found in older age. Karyotypic complexity varied within chromosome 5/7 combination groups; those containing -5, -5/-7, -5/del(7q), del(5q)/-7 or del(5q)/del(7q) combinations were significantly more frequently complex than those containing -7 and del(7q) (P < 0.01, chi2 test). Additional recurring cytogenetic abnormalities within complex karyotypes containing chromosome 5/7 combinations included (in order of frequency), abnormalities of chromosomes 17, 12, 3 and 18. Complex karyotypes not involving chromosomes 5 or 7 represented 30% of all complex karyotypes, occurred in younger patients than those involving chromosomes 5 and 7, and frequently included additional trisomy 8 (26%). In conclusion, we describe subgroups within adverse karyotypes, with different demographics, degree of complexity and additional chromosome abnormalities.     

Postmenopausal estrogen and progestin use in relation to breast cancer risk.

Epidemiological evidence now consistently supports a modest increase in breast cancer risk among women using postmenopausal hormones, usually estrogens.Less is known regarding how the addition of progestin affects breast cancer risk. The objective of this study was to investigate the type and duration of postmenopausal therapy and breast cancer risk. We performed a multicenter population-based case-control study set in Massachusetts, New Hampshire, and Wisconsin. The subjects were 5298 postmenopausal women (age range, 50-79 years) with a new diagnosis of invasive breast cancer from statewide tumor registries. For comparison, 5571 controls were randomly selected from population lists. Participants completed a structured telephone interview covering hormone use and breast cancer risk factors. Multivariable regression models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs). The RR for breast cancer increased with longer durations of hormone use, about 2%/year for estrogen alone (RR, 1.02; 95% CI, 1.01-1.03) and 4%/year for estrogen-progestin use (RR, 1.04; 95% CI, 1.01-1.08). Estrogen-progestin use that was both recent and long term (>5 years in duration) was more strongly associated with breast cancer risk (RR, 1.57; 95% CI, 1.15-2.14) than similar use of estrogen alone (RR, 1.39; 95% CI, 1.17-1.65). In estrogen-progestin users, risks were similar for sequential and continuous use regimens but perhaps stronger for lobular than ductal breast cancer. Use of progestin alone was associated with a doubling of risk (RR, 2.09; 95% CI, 1.07-4.07 for ever use versus nonuse). Estrogen-progestin use, both sequential and continuous, appears to be more strongly associated with risk of breast cancer than use of estrogen alone.     

A prospective study of drinking patterns in relation to risk of type 2 diabetes among men

Using data from a 12-year prospective study, we determined the importance of the pattern of alcohol consumption as a risk factor for type 2 diabetes in a cohort of 46,892 U.S. male health professionals who completed biennial postal questionnaires. Overall, 1,571 new cases of type 2 diabetes were documented. Compared with zero alcohol consumption, consumption of 15-29 g/day of alcohol was associated with a 36% lower risk of diabetes (RR = 0.64; 95% CI 0.53-0.77). This inverse association between moderate consumption and diabetes remained if light drinkers rather than abstainers were used as the reference group (RR = 0.60, CI 0.50-0.73). There were few heavy drinkers, but the inverse association persisted to those drinking >/=50 g/day of alcohol (RR = 0.60, CI 0.43-0.84). Frequency of consumption was inversely associated with diabetes. Consumption of alcohol on at least 5 days/week provided the greatest protection, even when less than one drink per drinking day was consumed (RR = 0.48, CI 0.27-0.86). Compared with infrequent drinkers, for each additional day per week that alcohol was consumed, risk was reduced by 7% (95% CI 3-10%) after controlling for average daily consumption. There were similar and independent inverse associations for beer, liquor, and white wine. Our findings suggested that frequent alcohol consumption conveys the greatest protection against type 2 diabetes, even if the level of consumption per drinking day is low. Beverage choice did not alter risk.