Plasma lycopene, other carotenoids, and retinol and the risk of cardiovascular disease in women

BACKGROUND: Growing evidence suggests that lycopene has significant in vitro antioxidant potential. Lycopene has rarely been tested in prospective studies for its role in cardiovascular disease (CVD) prevention. OBJECTIVE: We examined the association between plasma lycopene and the risk of CVD in middle-aged and elderly women. DESIGN: A prospective, nested, case-control study was conducted in 39 876 women initially free of CVD and cancer in the Women's Health Study. Baseline blood samples were collected from 28 345 (71%) of the women. During a mean of 4.8 y of follow-up, we identified 483 CVD cases and 483 control subjects matched by age, smoking status, and follow-up time. Plasma lycopene, other carotenoids, retinol, and total cholesterol were measured. RESULTS: In analyses matched for age and smoking, with adjustment for plasma cholesterol, the relative risks (RRs) and 95% CIs of CVD in increasing quartiles of plasma lycopene were 1.00 (referent), 0.78 (95% CI: 0.55, 1.11), 0.56 (0.39, 0.82), and 0.62 (0.43, 0.90). In multivariate models, the RRs were 1.00 (referent), 0.94 (0.60, 1.49), 0.62 (0.39, 1.00), and 0.67 (0.41, 1.11); those in the upper compared with the lower half of plasma lycopene had an RR of 0.66 (0.47, 0.95). For CVD, exclusive of angina, women in the upper 3 quartiles had a significant multivariate 50% risk reduction compared with those in the lowest quartile. The stepwise addition of individual plasma carotenoids did not affect the RRs. CONCLUSIONS: Higher plasma lycopene concentrations are associated with a lower risk of CVD in women. These findings require confirmation in other cohorts, and the determinants of plasma lycopene concentrations need to be better understood.     

Plasma lycopene, other carotenoids, and retinol and the risk of cardiovascular disease in men

BACKGROUND: Emerging evidence suggests a possible role of lycopene in the primary prevention of cardiovascular disease (CVD). OBJECTIVE: We examined whether plasma lycopene concentrations in the Physicians' Health Study were associated with CVD in a prospective, nested, case-control design. DESIGN: Baseline blood samples were collected starting in 1996. During a mean follow-up of 2.1 y, we identified 499 cases of CVD (confirmed myocardial infarction, stroke, CVD death, or revascularization procedures) and an equal number of men free of CVD and matched for age (x: 69.7 y), follow-up time, and smoking status. We collected self-reported coronary disease risk factors and measured plasma carotenoids, retinol, lipids, and C-reactive protein. RESULTS: In matched analyses with additional adjustment for plasma total cholesterol and randomized treatment, the relative risks (RRs) of CVD for men in the lowest to highest quartiles of plasma lycopene were 1.00 (reference), 0.92, 1.04, and 0.95 (P for linear trend = 0.93). With multivariate adjustment, the RRs of total CVD were 1.00 (reference), 1.08, 0.94, and 1.03 (P for linear trend = 0.98). For important vascular events (241 cases), excluding revascularization procedures, the multivariate RRs remained nonsignificant (P for linear trend = 0.50). Adding plasma carotenoids, lipids, or C-reactive protein to multivariate models had a minimal effect on the RRs of total CVD for plasma lycopene. Compared with lycopene, higher concentrations of plasma lutein/zeaxanthin and retinol suggested a moderate increase in CVD risk, whereas no association was found for beta-cryptoxanthin, alpha-carotene, and beta-carotene. CONCLUSIONS: Higher plasma lycopene concentrations were not associated with the risk of CVD in this study of older men. Further evaluation in diverse populations is necessary.     

Serum lycopene,other serum carotenoids,and risk of prostate cancer in US Blacks and Whites

Epidemiologic studies investigating the relation between individual carotenoids and risk of prostate cancer have produced inconsistent results. To further explore these associations and to search for reasons prostate cancer incidence is over 50% higher in US Blacks than Whites, the authors analyzed the serum levels of individual carotenoids in 209 cases and 228 controls in a US multicenter, population-based case-control study (1986-1989) that included comparable numbers of Black men and White men aged 40-79 years. Lycopene was inversely associated with prostate cancer risk (comparing highest with lowest quartiles, odds ratio (OR) = 0.65, 95% confidence interval (CI): 0.36, 1.15; test for trend, p = 0.09), particularly for aggressive disease (comparing extreme quartiles, OR = 0.37, 95% CI: 0.15, 0.94; test for trend, p = 0.04). Other carotenoids were positively associated with risk. For all carotenoids, patterns were similar for Blacks and Whites. However, in both the controls and the Third National Health and Nutrition Examination Survey, serum lycopene concentrations were significantly lower in Blacks than in Whites, raising the possibility that differences in lycopene exposure may contribute to the racial disparity in incidence. In conclusion, the results, though not statistically significant, suggest that serum lycopene is inversely related to prostate cancer risk in US Blacks and Whites.     

The consumption of lycopene and tomato-based food products is not associated with the risk of type 2 diabetes in women

Lycopene is a major carotenoid with potent antioxidant properties that may provide protection against the development of type 2 diabetes mellitus (DM). In this study we examined the association between baseline dietary intakes of lycopene, lycopene-containing foods, and the subsequent development of type 2 DM in a large prospective cohort study. We analyzed a total of 35,783 women from the United States, aged > or =45 y and free from self-reported cardiovascular disease, cancer, and DM at baseline. Intakes of lycopene and total and individual tomato-based food products were assessed by a 131-item-validated semiquantitative food-frequency questionnaire. During a median follow-up of 10.2 y, 1544 cases of incident type 2 DM were documented. After adjusting for age, total energy intake, randomized treatment assignment, body mass index, and other known DM risk factors, the multivariate-adjusted relative risks and 95% CI of type 2 DM across increasing quintiles of dietary lycopene, were 1.00 (baseline), 1.10 (0.94-1.29), 1.10 (0.94-1.29), and 1.07 (0.91-1.26) (P linear trend = 0.56). Compared with women who consumed <1.5 servings/wk total tomato-based food products, women who consumed 1.5 to <4, 4 to <7, 7 to <10, and > or =10 servings/wk had multivariate relative risks (95% CI) of 1.03 (0.88-1.20), 1.02 (0.87-1.20), 1.09 (0.89-1.33), and 1.04 (0.80-1.36), respectively (P linear trend = 0.54). The associations for individual tomato-based food products were similar to the results for the combination of all tomato products. Our study found little evidence for an association between dietary intake of lycopene or lycopene-containing foods and the risk of type 2 DM.     

Low-carbohydrate-diet score and risk of type 2 diabetes in women

BACKGROUND: Low-carbohydrate weight-loss diets remain popular; however, the long-term effects of these diets are not known. OBJECTIVE: The objective was to examine the association between low-carbohydrate-diet score and risk of type 2 diabetes DESIGN: We prospectively examined the association between low-carbohydrate-diet score (based on percentage of energy as carbohydrate, fat, and protein) and risk of diabetes among 85 059 women in the Nurses' Health Study. RESULTS: During 20 y of follow-up, we documented 4670 cases of type 2 diabetes. The multivariate relative risk (RR) of diabetes, after adjustment for body mass index and other covariates, in a comparison of the highest decile of low-carbohydrate-diet score with the lowest was 0.90 (95% CI: 0.78, 1.04; P for trend = 0.26). The multivariate RR for the comparison of extreme deciles of low-carbohydrate-diet score based on total carbohydrate, animal protein, and animal fat was 0.99 (95% CI: 0.85, 1.16; P for trend = 1.0), whereas the RR for a low-carbohydrate-diet score based on total carbohydrate, vegetable protein, and vegetable fat was 0.82 (95% CI: 0.71, 0.94; P for trend = 0.001). A higher dietary glycemic load was strongly associated with an increased risk of diabetes in a comparison of extreme deciles (RR: 2.47; 95% CI: 1.75, 3.47; P for trend < 0.0001)). A higher carbohydrate consumption was also associated with an increased risk of diabetes in a comparison of extreme deciles (RR: 1.26; 95% CI: 1.07, 1.49; P for trend = 0.003). CONCLUSION: These data suggest that diets lower in carbohydrate and higher in fat and protein do not increase the risk of type 2 diabetes in women. In fact, diets rich in vegetable sources of fat and protein may modestly reduce the risk of diabetes.     

E-selectin genotypes and risk of type 2 diabetes in women

Endothelial dysfunction increases risk for type 2 diabetes. We examined whether variation in the gene for E-selectin (SELE), a biomarker of endothelial dysfunction, was associated with levels of E-selectin or diabetes quantitative traits (including fasting levels of insulin and hemoglobin A(1c)) in 719 nondiabetic participants of the Nurses' Health Study or with risk of diabetes in 602 incident (over 10 years of follow-up) cases and 655 control women matched for age, race, and fasting status. Variation in three single nucleotide polymorphisms previously associated with cardiovascular disease risk and having effects on E-selectin function, S128R, G98T, and L554F, was not significantly (p > 0.05) associated with levels of E-selectin or diabetes quantitative traits, or with risk of incident diabetes in the primary analysis. Among women with low levels of subclinical inflammation (C-reactive protein levels below the population median), S128R R allele carriers had a diabetes risk factor-adjusted relative risk of incident diabetes of 1.71 (95% confidence interval, 1.04 to 2.81) relative to those with the SS genotype. Apart from an association in this subgroup, we conclude that the E-selectin variants we examined are not important genetic risk factors for type 2 diabetes in women.     

Dietary fat intake and risk of type 2 diabetes in women

BACKGROUND: The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear. OBJECTIVE: Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes. DESIGN: We prospectively followed 84204 women aged 34-59 y with no diabetes, cardiovascular disease, or cancer in 1980. Detailed dietary information was assessed at baseline and updated in 1984, 1986, and 1990 by using validated questionnaires. Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates. RESULTS: During 14 y of follow-up, 2507 incident cases of type 2 diabetes were documented. Total fat intake, compared with equivalent energy intake from carbohydrates, was not associated with risk of type 2 diabetes; for a 5% increase in total energy from fat, the relative risk (RR) was 0.98 (95% CI: 0.94, 1.02). Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes. However, for a 5% increase in energy from polyunsaturated fat, the RR was 0.63 (0.53, 0.76; P < 0.0001) and for a 2% increase in energy from trans fatty acids the RR was 1.39 (1.15, 1.67; P = 0.0006). We estimated that replacing 2% of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40% lower risk (RR: 0.60; 95% CI: 0.48, 0.75). CONCLUSIONS: These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of type 2 diabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially.     

Potato and french fry consumption and risk of type 2 diabetes in women

BACKGROUND: Potatoes, a high glycemic form of carbohydrate, are hypothesized to increase insulin resistance and risk of type 2 diabetes. OBJECTIVE: The objective was to examine prospectively the relation between potato consumption and the risk of type 2 diabetes. DESIGN: We conducted a prospective study of 84,555 women in the Nurses' Health Study. At baseline, the women were aged 34-59 y, had no history of chronic disease, and completed a validated food-frequency questionnaire. The participants were followed for 20 y with repeated assessment of diet. RESULTS: We documented 4496 new cases of type 2 diabetes. Potato and french fry consumption were both positively associated with risk of type 2 diabetes after adjustment for age and dietary and nondietary factors. The multivariate relative risk (RR) in a comparison between the highest and the lowest quintile of potato intake was 1.14 (95% CI: 1.02, 1.26; P for trend = 0.009). The multivariate RR in a comparison between the highest and the lowest quintile of french fry intake was 1.21 (95% CI: 1.09, 1.33; P for trend < 0.0001). The RR of type 2 diabetes was 1.18 (95% CI: 1.03, 1.35) for 1 daily serving of potatoes and 1.16 (95% CI: 1.05, 1.29) for 2 weekly servings of french fries. The RR of type 2 diabetes for substituting 1 serving potatoes/d for 1 serving whole grains/d was 1.30 (95% CI: 1.08, 1.57). The association between potato consumption and risk of type 2 diabetes was more pronounced in obese women. CONCLUSIONS: Our findings suggest a modest positive association between the consumption of potatoes and the risk of type 2 diabetes in women. This association was more pronounced when potatoes were substituted for whole grains.     

Plasma carotenoids, retinol, and tocopherols and risk of breast cancer

The roles of carotenoids, retinol, and tocopherols in breast cancer etiology have been inconclusive. The authors prospectively assessed the relations between plasma alpha-carotene, beta-carotene, beta-cryptoxanthin, lycopene, lutein/zeaxanthin, retinol, alpha-tocopherol, and gamma-tocopherol and breast cancer risk by conducting a nested case-control study using plasma collected from women enrolled in the Nurses' Health Study. A total of 969 cases of breast cancer diagnosed after blood draw and prior to June 1, 1998, were individually matched to controls. The multivariate risk of breast cancer was 25-35% less for women with the highest quintile compared with that for women with the lowest quintile of alpha-carotene (odds ratio (OR) = 0.64, 95% confidence interval (CI): 0.47, 0.88; p(trend) = 0.01), beta-carotene (OR = 0.73, 95% CI: 0.53, 1.02; p(trend) = 0.01), lutein/zeaxanthin (OR = 0.74, 95% CI: 0.55, 1.01; p(trend) = 0.04), and total carotenoids (OR = 0.76, 95% CI: 0.55, 1.05; p(trend) = 0.05). The inverse association observed with alpha-carotene and breast cancer was greater for invasive cancers with nodal metastasis. The authors conclude that some carotenoids are inversely associated with breast cancer. Although the association was strongest for alpha-carotene, the high degree of collinearity among plasma carotenoids limits our ability to conclude that this association is specific to any individual carotenoid.     

吸烟与糖代谢异常关系研究进展

  目的  探讨男性吸烟剂量与2型糖尿病患病的关系。  方法  2016年7 — 12月,在广东省中山市采用多阶段抽样方法抽取6 150名居民进行问卷调查、体格检查和实验室检测,使用logistic回归模型和限制性立方样条模型,分析男性吸烟者的吸烟剂量与2型糖尿病患病的关联性。  结果  总人群吸烟率为18.24 %,男性吸烟率为38.16 %;总人群糖尿病患病率为5.48 %,男性吸烟者2型糖尿病患病率为6.13 %;调整年龄、户籍、婚姻、BMI、受教育水平、家庭月均收入、高血压史等因素后,多因素logistic回归分析显示,现在吸烟者与2型糖尿病患病有关（OR = 1.45,95 % CI = 1.10～1.92;OR_调整 = 1.43,95 % CI = 1.10～1.90）;限制性立方样条模型（RCS）显示,男性吸烟者吸烟数量、吸烟指数与2型糖尿病呈非线性剂量 – 反应关系（非线性检验,P < 0.05）。  结论  男性吸烟的剂量与2型糖尿病发病有关。     

Plasma concentrations of carotenoids, retinol, and tocopherols in preeclamptic and normotensive pregnant women

This case-control study was conducted in Lima, Peru, from June 1997 through January 1998 to assess whether plasma concentrations of carotenoids (alpha-carotene, beta-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin), retinol, and tocopherols (alpha-tocopherol and gamma-tocopherol) are decreased in women with preeclampsia. A total of 125 pregnant women with preeclampsia and 179 normotensive pregnant women were included. Plasma concentrations of antioxidants were determined using high performance liquid chromatography. After adjusting for maternal demographic, behavioral, and reproductive characteristics and total plasma lipid concentrations, the authors found a linear increase in risk of preeclampsia with increasing concentrations of alpha-tocopherol (odds ratio of the highest quartile = 3.13; 95% confidence interval: 1.06, 9.23, with the lowest quartile as the reference group; p value of the test of linear trend = 0.040). The risk of preeclampsia decreased across increasing quartiles of concentrations for retinol (odds ratio of the highest quartile = 0.32; 95% confidence interval: 0.15, 0.69, with the lowest quartile as the reference group; p value of the test of linear trend = 0.001). Some of these results are inconsistent with the prevailing hypothesis that preeclampsia is an antioxidant-deficient state. Preliminary findings confirm an earlier observation of increased plasma concentrations of alpha-tocopherol among women with preeclampsia as compared with normotensive pregnant women.     

Vegetable but not fruit consumption reduces the risk of type 2 diabetes in Chinese women

We examined associations between fruit and vegetable intake and the incidence of type 2 diabetes (T2D) in a population-based prospective study of 64,191 women with no history of T2D or other chronic diseases at study recruitment and with valid dietary information. Dietary intake was assessed by in-person interviews using a validated FFQ. During 297,755 person-years of follow-up, 1608 new cases of T2D were documented. We used a Cox regression model to evaluate the association of fruit and vegetable intake (g/d) with the risk of T2D. Quintiles of vegetable intake and T2D were inversely associated. The relative risk for T2D for the upper quintile relative to the lower quintile of vegetable intake was 0.72 (95%CI: 0.61-0.85; P < 0.01) in multivariate analysis. Individual vegetable groups were all inversely and significantly associated with the risk of T2D. Fruit intake was not associated with the incidence of diabetes in this population. Our data suggest that vegetable consumption may protect against the development of T2D.     

饮酒及其他生活方式因子的交互作用与2型糖尿病发生风险

目的探讨饮酒及其他生活方式因子的交互作用对2型糖尿病(type 2diabetes mellitus,T2DM)发生风险的影响。方法 2015年6月—2016年2月,利用简单随机抽样方法,在淮南市东方医院与淮南市体检中心分别选取320例T2DM患者和640例同期健康体检者,比较两组间一般人口学信息、饮酒、吸烟、体力活动和饮食行为方面的差异,运用非条件Logistic回归与广义多因子降维法(GMDR)进行统计分析。结果 (1)Logistic回归分析结果显示:调整混杂因素后,各食物条目摄入得分相对于Q1,粮谷类(OR=0.301,95%CI 0.153~0.628)、蔬菜水果类(OR=0.444,95%CI 0.245~0.806)、奶及奶制品(OR=0.510,95%CI 0.329~0.790)、豆类(OR=0.434,95%CI 0.212~0.901)、红肉类(OR=0.461,95%CI 0.229~0.926)、西方食物类(OR=0.223,95%CI 0.076~0.652)、含糖饮料类(OR=0.150,95%CI0.035~0.643)摄入得分为Q5以及体质指数<24.0(OR=0.189,95%CI 0.109~0.329)为罹患T2DM的保护因素;而经常饮酒(OR=3.936,95%CI 1.145~8.734)、中等强度体力活动<5次/周(OR=1.558,95%CI 1.013~2.876)为罹患T2DM的危险因素。(2)相乘交互作用分析显示:经常饮酒分别与摄入粮谷类(Q5)(OR=0.852,95%CI 0.765~0.949)、蔬菜水果类(Q5)(OR=0.862,95%CI 0.757~0.982)及中等体力活动≥5次/周(OR=0.613,95%CI 0.468~0.803)间存在相乘交互作用。(3)相加交互作用分析显示:经常饮酒分别与高摄入红肉、含糖饮料及中等体力活动≥5次/周间存在相加交互作用。(4)GMDR法分析显示:含糖饮料、红肉和经常饮酒三因素间存在交互作用共同影响T2DM的发生(P=0.001)。结论经常饮酒与其他多种可控因素间存在交互作用共同影响T2DM的发生。     

Weight cycling and the risk of developing type 2 diabetes among adult women in the United States

OBJECTIVE: To assess the role of weight cycling independent of BMI and weight change in predicting the risk of developing type 2 diabetes. RESEARCH METHODS AND PROCEDURES: A six-year follow-up of 46,634 young and middle-aged women in the Nurses' Health Study II was conducted. Women who had intentionally lost > or = 20 lbs at least three times between 1989 and 1993 were classified as severe weight cyclers. Women who had intentionally lost > or = 10 lbs at least three times were classified as mild weight cyclers. The outcome was physician-diagnosed type 2 diabetes. RESULTS: Between 1989 and 1993, approximately 20% of the women were mild weight cyclers, and 1.6% were severe weight cyclers. BMI in 1993 was positively associated with weight-cycling status (p < 0.001). During 6 years of follow-up (1993 to 1999), 418 incident cases of type 2 diabetes were documented. BMI in 1993 had a strong association with the risk of developing diabetes. Compared with women with a BMI between 17 and 22 kg/m(2), those with a BMI between 25 and 29.9 kg/m(2) were approximately seven times more likely to develop diabetes, and those with a BMI > or = 35 kg/m(2) were 63 times more likely to be diagnosed with type 2 diabetes. After adjustment for BMI, neither mild (relative risk = 1.11, 95% confidence interval, 0.89 to 1.37) nor severe (relative risk = 1.39, 95% confidence interval, 0.90 to 2.13) weight cycling predicted risk of diabetes. DISCUSSION: Weight cycling was strongly associated with BMI, but it was not independently predictive of developing type 2 diabetes.     

Dietary pattern, inflammation, and incidence of type 2 diabetes in women

BACKGROUND: Inflammation is considered a key mechanism leading to type 2 diabetes, but dietary exposures that lead to inflammation and diabetes are largely unknown. OBJECTIVE: Our objective was to investigate the relation between a dietary pattern associated with biomarkers of inflammation and the incidence of type 2 diabetes. DESIGN: We conducted a nested case-control study of 656 cases of type 2 diabetes and 694 controls among women in the Nurses' Health Study and 2 prospective cohort studies of 35,340 women in the Nurses' Health Study and 89,311 women in the Nurses' Health Study II who were followed for incident diabetes. RESULTS: Through the use of reduced rank regression, we identified a dietary pattern that was strongly related to inflammatory markers in the nested case-control study. This pattern, which was high in sugar-sweetened soft drinks, refined grains, diet soft drinks, and processed meat but low in wine, coffee, cruciferous vegetables, and yellow vegetables, was associated with an increased risk of diabetes (multivariate-adjusted odds ratio comparing extreme quintiles: 3.09; 95% CI: 1.99, 4.79). We identified 1517 incident cases of confirmed type 2 diabetes in the Nurses' Health Study (458,991 person-years) and 724 incident cases in the Nurses' Health Study II (701,155 person-years). After adjustment for body mass index and other potential lifestyle confounders, the relative risks comparing extreme quintiles of the pattern were 2.56 (95% CI: 2.10, 3.12; P for trend < 0.001) in the Nurses' Health Study and 2.93 (95% CI: 2.18, 3.92; P for trend < 0.001) in the Nurses' Health Study II. CONCLUSION: The dietary pattern identified may increase chronic inflammation and raise the risk of developing type 2 diabetes.     

Depression,neighborhood deprivation and risk of type 2 diabetes

Neighborhood characteristics have been associated with both depression and diabetes, but to date little attention has been paid to whether the association between depression and diabetes varies across different types of neighborhoods. This prospective study examined the relationship between depression, neighborhood deprivation, and risk of type 2 diabetes among 336,340 adults from a national-representative sample of primary care centers in Sweden (2001–2007). Multi-level logistic regression models were used to assess associations between depression and risk of type 2 diabetes across affluent and deprived neighborhoods. After accounting for demographic, individual-level socioeconomic, and health characteristics, depression was significantly associated with risk of diabetes (odds ratio (OR): 1.10, 95% confidence interval (CI): 1.06–1.14), as was neighborhood deprivation (OR for high vs. low deprivation: 1.66, 95% CI: 1.22–1.34). The interaction term between depression and neighborhood deprivation was non-significant, indicating that the relationship between depression and diabetes risk is similar across levels of neighborhood socioeconomic deprivation.