Gene-lifestyle interaction on risk of type 2 diabetes: A systematic review.

The pathophysiological influence of gene-lifestyle interactions on the risk to develop type 2 diabetes (T2D) is currently under intensive research. This systematic review summarizes the evidence for gene-lifestyle interactions regarding T2D incidence. MEDLINE, EMBASE, and Web of Science were systematically searched until 31 January 2019 to identify publication with (a) prospective study design; (b) T2D incidence; (c) gene-diet, gene-physical activity, and gene-weight loss intervention interaction; and (d) population who are healthy or prediabetic. Of 66 eligible publications, 28 reported significant interactions. A variety of different genetic variants and dietary factors were studied. Variants at TCF7L2 were most frequently investigated and showed interactions with fiber and whole grain on T2D incidence. Further gene-diet interactions were reported for, eg, a western dietary pattern with a T2D-GRS, fat and carbohydrate with IRS1 rs2943641, and heme iron with variants of HFE. Physical activity showed interaction with HNF1B, IRS1, PPARγ, ADRA2B, SLC2A2, and ABCC8 variants and weight loss interventions with ENPP1, PPARγ, ADIPOR2, ADRA2B, TNFα, and LIPC variants. However, most findings represent single study findings obtained in European ethnicities. Although some interactions have been reported, their conclusiveness is still low, as most findings were not yet replicated across multiple study populations.

Intake of cocoa products and risk of type-2 diabetes: the multiethnic cohort.

BACKGROUND/OBJECTIVES: As cocoa products may be protective against chronic disease due to their polyphenol content, the current study determined the association of chocolate consumption and flavanol intake with type-2 diabetes (T2D) incidence in the Multiethnic Cohort (MEC) Study. SUBJECTS/METHODS: The analysis included 151,691 participants of Native Hawaiian, Japanese American, Latino, African American, and white ancestry with 8487 incident T2D cases after 7.8 ± 3.5 years of follow-up. T2D status was based on three self-reports and confirmed by at least one of three administrative data sources. Dietary intake was assessed using a validated quantitative food frequency questionnaire, and flavanols from cocoa products were estimated from self-reported consumption of chocolate candy and drinks. Cox hazard regression, adjusted for potential confounders was applied to estimate hazard ratios (HR) and 95% confidence intervals (CI). RESULTS: For chocolate candy, both the highest vs. lowest (≥10 vs. <1 g/day) consumption (HR = 0.90; 95% CI, 0.83-0.97; ptrend = 0.01) and the frequency (≥4/week vs. <1/month) of intake (HR = 0.81; 95% CI, 0.72-0.91; ptrend = 0.0002) were inversely associated with T2D. The estimated flavanol intake from cocoa products (≥3 vs. <1 mg/day) also showed an inverse association with T2D risk (HR = 0.93; 95% CI, 0.88-0.99; ptrend = 0.02). Significant interaction terms indicated that the inverse relation was limited to Japanese Americans, normal-weight individuals, and to those without comorbidities. CONCLUSIONS: The current study confirms previous reports that participants with high intake of chocolate products and cocoa-derived flavanols experience a reduced risk of developing T2D even after controlling for sugar intake, diet quality, and other aspects of the diet.

Low diet quality and the risk of stroke mortality: the multiethnic cohort study.

BACKGROUND/OBJECTIVES: Several diets, e.g., those low in fruits/vegetables, high in sodium, and red/processed meat, have been related to a higher stroke risk. We investigated stroke mortality associated with a priori diet-quality indices in the Multiethnic Cohort study. SUBJECTS/METHODS: Based on 172,043 observations including 3548 stroke deaths, we investigated the Healthy Eating Index-2010 (HEI-2010), the Alternative HEI-2010, the alternate Mediterranean diet score, and the Dietary Approaches to Stop Hypertension index in relation to stroke mortality. Using Cox regression, we estimated adjusted population attributable risks (PAR) and hazard ratios (HR) for tertiles of the indices while adjusting for relevant confounders. RESULTS: The associations between all diet-quality indices and stroke mortality were consistent in direction; a low-quality diet was associated with a greater risk of stroke death, but the HEI-2010 was the strongest predictor. The PAR for stroke death based on HEI-2010 was 7.9% (95%-CI: 3.7-12.2%), indicating the preventable percentage of deaths if the total population had the same diet quality as those in the highest tertile for this diet-quality index. The lowest as compared to the highest tertile of the HEI-2010 was associated with a 1.23-fold (95%-CI: 1.13-1.34) risk. The PARs for low and medium adherence to the indices were similar by sex and follow-up time, but varied by ethnicity, with the highest PAR in Whites (15.4%) and no association in Latinos. CONCLUSIONS: Findings for four diet-quality indices, in particular the HEI-2010, indicated that diet quality acts as an independent risk factor for stroke mortality. Promotion of a high diet quality could have a substantial impact on the prevention of stroke deaths.

Sleep duration and incidence of type 2 diabetes: the Multiethnic Cohort.

OBJECTIVES: As an emerging risk factor for the rising incidence of type 2 diabetes, we examined sleep duration in relation to type 2 diabetes and several biomarkers. DESIGN: Prospective cohort recruited 1993-1996. SETTING: The Multiethnic Cohort in Hawaii and California. PARTICIPANTS: A cohort of 151,691 White, African American, Japanese American, Native Hawaiian, and Latino participants; 9695 cohort members had biomarker measurements. MEASUREMENTS: Sleep duration was self-reported at cohort entry. Diabetes status was obtained from 3 questionnaires and confirmed by 3 administrative data sources. Biomarkers were measured by standard assays 9.6±2.1 years after cohort entry. We estimated diabetes risk as a time-varying outcome using Cox regression adjusted for body mass index assessed at 3 time points and other known confounders and computed adjusted means of biomarkers by sleep hours. RESULTS: During 7.9±3.5 years of follow-up, 8487 new diabetes cases were diagnosed. Long sleep duration (≥9 hours), as compared with 7-8 hours, was significantly associated with higher incidence (hazard ratio, 1.12; 95% confidence interval 1.04-1.21), but the 4% elevated incidence for short sleep duration (≤6 hours) did not reach significance (95% confidence interval 0.99-1.09). After stratification, the associations appeared stronger in Japanese American than other ethnic groups and in participants without comorbidity. Hours of sleep were positively associated with C-reactive protein and triglycerides and inversely related to high-density lipoprotein cholesterol and adiponectin but not with leptin levels and homeostatic model assessment of insulin resistance. CONCLUSION: In this multiethnic population, the 12% higher diabetes risk for long sleep hours may be mediated through inflammation, a poor lipid profile, and lower adiponectin levels.

A priori-defined diet quality indices, biomarkers and risk for type 2 diabetes in five ethnic groups: the Multiethnic Cohort.

Dietary indices have been related to risk for type 2 diabetes (T2D) predominantly in white populations. The present study evaluated this association in the ethnically diverse Multiethnic Cohort and examined four diet quality indices in relation to T2D risk, homoeostatic model assessment-estimated insulin resistance (HOMA-IR) and biomarkers of dyslipidaemia, inflammation and adipokines. The T2D analysis included 166 550 white, African American, Native Hawaiian, Japanese American and Latino participants (9200 incident T2D cases). Dietary intake was assessed at baseline using a quantitative FFQ and T2D status was based on three self-reports and confirmed by administrative data. Biomarkers were assessed about 10 years later in a biomarker subcohort (n 10 060). Sex- and ethnicity-specific hazard ratios were calculated for the Healthy Eating Index-2010 (HEI-2010), the alternative HEI-2010 (AHEI-2010), the alternate Mediterranean diet score (aMED) and the Dietary Approaches to Stop Hypertension (DASH). Multivariable-adjusted means of biomarkers were compared across dietary index tertiles in the biomarker subcohort. The AHEI-2010, aMED (in men only) and DASH scores were related to a 10-20 % lower T2D risk, with the strongest associations in whites and the direction of the relationships mostly consistent across ethnic groups. Higher scores on the four indices were related to lower HOMA-IR, TAG and C-reactive protein concentrations, not related to leptin, and the DASH score was directly associated with adiponectin. The AHEI-2010 and DASH were directly related to HDL-cholesterol in women. Potential underlying biological mechanisms linking diet quality and T2D risk are an improved lipid profile and reduced systemic inflammation and, with regards to DASH alone, an improved adiponectin profile.

Diet Quality in Midadulthood Predicts Visceral Adiposity and Liver Fatness in Older Ages: The Multiethnic Cohort Study.

OBJECTIVE: The relationship of diet quality assessed by established indices (HEI-2010, AHEI-2010, aMED, DASH) with adiposity measures was examined, especially visceral adipose tissue (VAT) and nonalcoholic fatty liver (NAFL). METHODS: Close to 2,000 participants of the Multiethnic Cohort completed validated food frequency questionnaires at cohort entry (1993-1996) and clinic visit (2013-2016) when they underwent whole-body dual-energy x-ray absorptiometry and abdominal magnetic resonance imaging scans. Linear regression was used to estimate mean values of adiposity measures by dietary index tertiles at baseline and standardized regression coefficients (ßs ) after adjusting for total adiposity and other covariates. Logistic regression of VAT and NAFL on dietary indices was also performed. RESULTS: Higher dietary quality scores at cohort entry were inversely related to all adiposity measures, with the strongest associations for percent liver fat (ßs = -0.14 to -0.08), followed by VAT (ßs = -0.11 to -0.05), BMI (ßs = -0.11 to -0.06), and total body fat (ßs = -0.09 to -0.05). Odds ratios adjusted for total adiposity ranged between 0.57 and 0.77 for NAFL and between 0.41 and 0.65 for high VAT when comparing the highest versus lowest tertiles of diet quality. CONCLUSIONS: These longitudinal findings indicate that maintaining a high-quality diet during mid-to-late adulthood may prevent adverse metabolic consequences related to VAT and NAFL.

Type II Diabetes, Obesity, and Breast Cancer Risk: The Multiethnic Cohort.

Background: Obesity has been more consistently associated with breast cancer than type II diabetes. This analysis examined the combination of the two factors in the Multiethnic Cohort (MEC).Methods: Women ages 45-75 years entered the MEC in 1993-1996 by completing a questionnaire. Type II diabetes status was self-reported at baseline, two follow-up questionnaires, and confirmed by administrative data. Cancers were identified from tumor registries and deaths through vital records until 2010. Cox regression was applied to estimate HRs and 95% confidence intervals (CI) for BMI and type II diabetes status alone and in combination.Results: Among 103,721 (25,146 white, 20,255 African American, 7,681 Native Hawaiian, 28,012 Japanese American, 22,627 Latina) women with 14,558 type II diabetes cases, 6,692 women developed breast cancer during 14.8 ± 4.1 years of follow-up. Type II diabetes was significantly associated with breast cancer risk (HR, 1.15; 95% CI, 1.07-1.23), but including body mass index (BMI) lowered the HR to 1.08 (95% CI, 1.00-1.16). Ethnic-specific BMI-adjusted models showed elevated risks for type II diabetes in Latinas only (HR, 1.30; 95% CI, 1.11-1.52). In contrast, obesity predicted statistically significant 21%-46% higher risks, after type II diabetes adjustment, in all ethnic groups except Latinas (HR, 1.17; 95% CI, 0.99-1.38).Conclusions: As reported previously, inclusion of BMI weakened the association of type II diabetes with breast cancer. Type II diabetes status, but not BMI, was primarily associated with higher breast cancer risk in Latinas.Impact: The role of obesity and type II diabetes in breast cancer etiology may differ by ethnicity suggesting metabolic differences related to obesity. Cancer Epidemiol Biomarkers Prev; 26(6); 854-61. ©2017 AACR.

Dietary Patterns Derived by Reduced Rank Regression Are Inversely Associated with Type 2 Diabetes Risk across 5 Ethnic Groups in the Multiethnic Cohort.

Background: Reduced rank regression (RRR) is an approach to identify dietary patterns associated with biochemical markers and risk of type 2 diabetes (T2D). Objective: We aimed to derive dietary patterns associated with adiponectin, leptin, C-reactive protein (CRP), and triglycerides (TGs) and to examine the prospective associations of these patterns with T2D risk in 5 ethnic/racial groups with differences in T2D rates. Methods: The Multiethnic Cohort (MEC) included 215,831 African-American, Japanese-American, Latino, Native Hawaiian, and white adults living in Hawaii and California who completed a validated quantitative food-frequency questionnaire in 1993-1996. T2D status was based on self-report with confirmation by administrative data. Serum CRP and TGs and plasma adiponectin and leptin were measured ∼10 y after baseline in a subset (n = 10,008) of participants. RRR was applied to dietary data and biomarker information of 10,008 MEC participants in the combined population and in each ethnic/racial group. RRR-derived dietary patterns, simplified by removal of foods that were not found to be important, were subsequently evaluated for association with T2D risk in 155,316 cohort members (8687 incident T2D cases diagnosed by 2010) by using Cox proportional hazards regression. Results: Combining ethnic/racial groups, we identified a dietary pattern low in processed and red meat, sugar-sweetened beverages, diet soft drinks, and white rice and high in whole grains, fruit, yellow-orange vegetables, green vegetables, and low-fat dairy that was inversely associated with CRP, TGs, and leptin and positively related to adiponectin. Comparing extreme tertiles, the dietary pattern predicted a 16-28% significantly lower T2D risk in the combined study population and also separately in African Americans, Japanese Americans, Latinos, Native Hawaiians, and whites. Ethnicity-specific derived patterns varied only modestly from the overall pattern and resulted in comparable associations with T2D. Conclusion: This identified dietary pattern may lower T2D risk through its impact on adipokines, by lowering chronic inflammation and dyslipidemia across 5 ethnic/racial groups.

Among 4 Diet Quality Indexes, Only the Alternate Mediterranean Diet Score Is Associated with Better Colorectal Cancer Survival and Only in African American Women in the Multiethnic Cohort.

BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer-related death in the United States, with a 5-y survival rate of ∼65%. Therefore, the identification of modifiable health factors to improve CRC survival is crucial. OBJECTIVE: We investigated the association of 4 prediagnostic a priori diet quality indexes with CRC-specific and all-cause mortality in the Multiethnic Cohort (MEC). METHODS: The MEC included >215,000 African-American, Native Hawaiian, Japanese-American, Latino, and white adults living in Hawaii and California who completed a validated quantitative food-frequency questionnaire in 1993-1996. CRC cases and deaths were identified through linkages to cancer registries and to state and national vital registries. Sex-specific HRs and 95% CIs were estimated for the Healthy Eating Index (HEI) 2010, the Alternative HEI (AHEI) 2010, the alternate Mediterranean Diet (aMED) score, and the Dietary Approaches to Stop Hypertension (DASH) index with CRC-specific and overall mortality as the primary outcomes. Ethnicity-specific analyses were the secondary outcomes. RESULTS: Among 4204 MEC participants diagnosed with invasive CRC through 2010, 1976 all-cause and 1095 CRC-specific deaths were identified. A higher aMED score was associated with lower CRC-specific mortality in women [HR continuous pattern score divided by its respective SD (HR1SD): 0.86; 95% CI: 0.77, 0.96] but not in men (HR1SD: 1.01; 95% CI: 0.92, 1.11). A higher aMED score was also associated with lower all-cause mortality in women (HR1SD: 0.88; 95% CI: 0.81, 0.96) but not in men (HR1SD: 1.00; 95% CI: 0.93, 1.07). The HEI-2010, AHEI-2010, and DASH index were not significantly associated with CRC-specific or with all-cause mortality. The inverse relation for the aMED score was limited to African Americans and to colon (compared with rectal) cancer. CONCLUSIONS: The aMED score was related to lower mortality only in African-American women (1 of 5 ethnic groups studied). The results should be interpreted with caution due to the small numbers of cases within ethnic groups and the issue of multiple testing.

Amino acids, lipid metabolites, and ferritin as potential mediators linking red meat consumption to type 2 diabetes.

BACKGROUND: Habitual red meat consumption was consistently related to a higher risk of type 2 diabetes in observational studies. Potentially underlying mechanisms are unclear. OBJECTIVE: This study aimed to identify blood metabolites that possibly relate red meat consumption to the occurrence of type 2 diabetes. DESIGN: Analyses were conducted in the prospective European Prospective Investigation into Cancer and Nutrition-Potsdam cohort (n = 27,548), applying a nested case-cohort design (n = 2681, including 688 incident diabetes cases). Habitual diet was assessed with validated semiquantitative food-frequency questionnaires. Total red meat consumption was defined as energy-standardized summed intake of unprocessed and processed red meats. Concentrations of 14 amino acids, 17 acylcarnitines, 81 glycerophospholipids, 14 sphingomyelins, and ferritin were determined in serum samples from baseline. These biomarkers were considered potential mediators of the relation between total red meat consumption and diabetes risk in Cox models. The proportion of diabetes risk explainable by biomarker adjustment was estimated in a bootstrapping procedure with 1000 replicates. RESULTS: After adjustment for age, sex, lifestyle, diet, and body mass index, total red meat consumption was directly related to diabetes risk [HR for 2 SD (11 g/MJ): 1.26; 95% CI: 1.01, 1.57]. Six biomarkers (ferritin, glycine, diacyl phosphatidylcholines 36:4 and 38:4, lysophosphatidylcholine 17:0, and hydroxy-sphingomyelin 14:1) were associated with red meat consumption and diabetes risk. The red meat-associated diabetes risk was significantly (P < 0.001) attenuated after simultaneous adjustment for these biomarkers [biomarker-adjusted HR for 2 SD (11 g/MJ): 1.09; 95% CI: 0.86, 1.38]. The proportion of diabetes risk explainable by respective biomarkers was 69% (IQR: 49%, 106%). CONCLUSION: In our study, high ferritin, low glycine, and altered hepatic-derived lipid concentrations in the circulation were associated with total red meat consumption and, independent of red meat, with diabetes risk. The red meat-associated diabetes risk was largely attenuated after adjustment for selected biomarkers, which is consistent with the presumed mediation hypothesis.

Associations of Erythrocyte Fatty Acids in the De Novo Lipogenesis Pathway with Proxies of Liver Fat Accumulation in the EPIC-Potsdam Study.

BACKGROUND: Biomarker fatty acids (FAs) reflecting de novo lipogenesis (DNL) are strongly linked to the risk of cardiometabolic diseases. Liver fat accumulation could mediate this relation. There is very limited data from human population-based studies that have examined this relation. OBJECTIVE: The aim of this study was to investigate the relation between specific FAs in the DNL pathway and liver fat accumulation in a large population-based study. METHODS: We conducted a cross-sectional analysis of a subsample (n = 1,562) of the EPIC-Potsdam study, which involves 27,548 middle-aged men and women. Baseline blood samples have been analyzed for proportions of 32 FAs in erythrocyte membranes (determined by gas chromatography) and biomarker concentrations in plasma. As indicators for DNL, the DNL-index (16:0 / 18:2n-6) and proportions of individual blood FAs in the DNL pathway were used. Plasma parameters associated with liver fat content (fetuin-A, ALT, and GGT) and the algorithm-based fatty liver index (FLI) were used to reflect liver fat accumulation. RESULTS: The DNL-index tended to be positively associated with the FLI and was positively associated with GGT activity in men (p for trend: 0.12 and 0.003). Proportions of 14:0 and 16:0 in erythrocytes were positively associated with fetuin-A, whereas 16:1n-7 were positively associated with the FLI and GGT activity (all p for trends in both sexes at least 0.004). Furthermore, the proportion of 16:1n-7 was positively related to fetuin-A in women and ALT activity in men (all p for trend at least 0.03). The proportion of 16:1n-9 showed positive associations with the FLI and GGT activity in men and fetuin-A in both sexes, whereas 18:1n-7 was positively associated with GGT activity in men (all p for trend at least 0.048). CONCLUSION: Findings from this large epidemiological study suggest that liver fat accumulation could link erythrocyte FAs in the DNL pathway to the risk of cardiometabolic diseases.

Evaluation of various biomarkers as potential mediators of the association between Δ5 desaturase, Δ6 desaturase, and stearoyl-CoA desaturase activity and incident type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition-Potsdam Study.

BACKGROUND: An association between desaturase activity and risk of type 2 diabetes (T2D) has been found in epidemiologic studies, but little is known about potential mediators of this association. OBJECTIVE: We aimed to investigate the potential role of diabetes-related biomarkers as mediators of the association between estimated Δ5 desaturase (D5D), Δ6 desaturase (D6D), and stearoyl-CoA desaturase (SCD) activity and T2D risk. DESIGN: We analyzed a case-cohort study (subcohort: n = 1533; verified incident T2D cases: n = 400), nested within the European Prospective Investigation into Cancer and Nutrition-Potsdam Study involving 27,548 middle-aged participants. We evaluated the impact of adjustment for several T2D-related biomarkers reflecting liver fat accumulation [reflected by γ-glutamyltransferase (GGT), alanine transaminase (ALT), fetuin-A, and the algorithm-based fatty liver index (FLI)], dyslipidemia (high-density lipoprotein cholesterol, triglycerides), inflammation [C-reactive protein (CRP)], and adiponectin on the association between D5D, D6D, and SCD activity, estimated with fatty acid product-to-precursor ratios derived from erythrocyte membrane proportions, and T2D risk. RESULTS: Estimated D5D activity was inversely associated with T2D risk, whereas D6D and SCD activities were positively associated with risk of T2D [HRs (95% CIs) (highest vs. lowest tertile): 0.51 (0.36, 0.73), 1.68 (1.18, 2.39), and 1.82 (1.29, 2.58), respectively]. The association between estimated D5D, D6D, and SCD activities and risk of T2D was statistically significantly and markedly attenuated after adjustment for the FLI and, to a lesser extent, after adjustment for triglycerides, whereas adjustment for other desaturase-associated biomarkers (CRP, fetuin-A, ALT, and GGT) did not lead to appreciable attenuations. CONCLUSIONS: Liver fat accumulation, as reflected by the FLI, and dyslipidemia, as reflected by triglycerides, may partly explain the association between estimated D5D, D6D, and SCD activity and T2D risk.

Association between the Fatty Liver Index and Risk of Type 2 Diabetes in the EPIC-Potsdam Study.

The fatty liver index (FLI) predicts fatty liver by using BMI, waist circumference, γ-glutamyltransferase and triglycerides. We investigated the association between the FLI and the risk of type 2 diabetes and evaluated to what extent single FLI components contribute to the diabetes risk. We analysed a case-cohort study (random sub-cohort: 1922; incident cases: 563) nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam study. The proportion of exposure effect (PEE) explained by single FLI components was evaluated and effect decomposition using inverse probability weighting (IPW) was applied. Women and men with a FLI ≥ 60 compared to those with a FLI < 30 had a multivariable-adjusted Hazard Ratio (HR) of 17.6; 95% confidence interval (CI) 11.1-28.0 and HR: 10.9; 95% CI 6.22-19.2, respectively. Adjustment for BMI or waist circumference attenuated this association in men [PEE BMI (95% CI) = 53.8% (43.9%-65.8%); PEE waist (95% CI) = 54.8% (44.2%-68.8%)]. In women, adjustment for waist circumference attenuated the association to a lesser degree than in men [PEE waist (95% CI) = 31.1%; (21.9%-43.1%)] while BMI had no appreciable effect [PEE BMI (95% CI) = 11.0% (2.68%-21.0%)]. γ-glutamyltransferase and triglycerides showed only a small attenuation in women [PEE GGT(95% CI) = 3.11% (-0.72%-4.48%); PEE TG (95% CI) = 6.36% (3.81%-9.92%)] and in men [PEE GGT = 0%; PEE TG (95% CI) = 6.23% (2.03%-11.8%)]. In women, the total effect was decomposed into a direct effect and 4 indirect effects (HR BMI = 1.10; HR waist = 1.28; HR GGT = 0.97 and HR TG = 1.03). In men, the 4 indirect effects were HR BMI = 1.25; HR waist = 1.29; HR GGT = 0.97 and HR TG = 0.99. These data suggest that the FLI, as a proxy for fatty liver, is associated with risk of type 2 diabetes. This association is only partly explained by standard estimates of overall and abdominal body fatness, particularly among women.

Disparity in diabetes risk across Native Hawaiians and different Asian groups: the multiethnic cohort.

We evaluated the impact of body mass index (BMI) and lifestyle risk factors on ethnic disparity in diabetes incidence among 89 198 Asian, Native Hawaiian, and white participants of the Multiethnic Cohort who completed multiple questionnaires. After 12 years of follow-up, 11 218 new cases were identified through self-report and health plan linkages. BMI was lowest in Chinese/Koreans, Japanese, and Filipinos (22.4, 23.5, and 23.9 kg/m(2)). Using Cox regression, the unadjusted hazard ratios were 1.9 (Chinese/Korean), 2.1 (Japanese, Mixed-Asian), 2.2 (Filipino), 2.5 (Native Hawaiian), and 2.6 (part-Asian) as compared with whites. With BMI added, the risk for Japanese, Filipinos, Chinese/Koreans, and mixed-Asians increased (8%-42%) but declined in part-Asians and Native Hawaiians (17%-31%). When lifestyle and dietary factors were also included, the risk was attenuated in all groups (6%-14%). Despite their lower BMI, Asian Americans have a higher diabetes risk than whites, but dietary and lifestyle factors do not account for the excess risk.

Erythrocyte membrane fatty acid fluidity and risk of type 2 diabetes in the EPIC-Potsdam study.

AIMS/HYPOTHESIS: The fluidity of cell membranes has been hypothesised as an important link in the association of fatty acids (FAs) with diabetes risk. The lipophilic index, which can be derived from the FA profile of blood or tissues, has recently been proposed as a novel measure of cell membrane FA fluidity. In this study we aimed to evaluate the lipophilic index in relation to the incidence of type 2 diabetes. METHODS: We applied a nested case-cohort design (n = 1,740, including 362 cases) within the EPIC-Potsdam study, which involves 27,548 middle-aged men and women. Erythrocyte membrane FA proportions were measured at baseline and physician-confirmed incident diabetes was assessed during a mean follow-up of 7.0 years. The lipophilic index was calculated as the sum of the products of the FA proportions with the respective FA melting points. RESULTS: After multivariable adjustments, including body size measures, there was a positive association between the lipophilic index and diabetes risk (HR comparing top with bottom quartile 1.59 (95% CI 1.08, 2.34), p for trend across quartiles = 0.005). Adjustment for FAs, which are considered established diabetes risk markers, did not substantially attenuate this association. CONCLUSIONS/INTERPRETATION: A high lipophilic index, reflecting lower membrane fluidity, may be associated with a higher risk of type 2 diabetes. Our data corroborate the hypothesis that membrane fluidity may be an important mediator that links intake and metabolism of FAs to diabetes risk.

A priori-defined diet quality indexes and risk of type 2 diabetes: the Multiethnic Cohort.

AIMS/HYPOTHESIS: Dietary patterns have been associated with the incidence of type 2 diabetes, but little is known about the impact of ethnicity on this relationship. This study evaluated the association between four a priori dietary quality indexes and risk of type 2 diabetes among white individuals, Japanese-Americans and Native Hawaiians in the Hawaii component of the Multiethnic Cohort. METHODS: After excluding participants with prevalent diabetes and missing values, the analysis included 89,185 participants (11,217 cases of type 2 diabetes). Dietary intake was assessed at baseline with a quantitative food frequency questionnaire designed for use in the relevant ethnic populations. Sex- and ethnicity-specific HRs were calculated for the Healthy Eating Index-2010 (HEI-2010), the Alternative HEI-2010 (AHEI-2010), the Alternate Mediterranean Diet Score (aMED) and the Dietary Approaches to Stop Hypertension (DASH). RESULTS: We observed significant inverse associations between higher DASH index scores and risk of type 2 diabetes in white men and women, as well as in Japanese-American women and Native Hawaiian men, with respective risk reductions of 37%, 31%, 19% and 21% (in the highest compared with the lowest index category). A higher adherence to the AHEI-2010 and aMED diet was related to a 13-28% lower risk of type 2 diabetes in white participants but not in other ethnic groups. No significant associations with risk of type 2 diabetes were observed for the HEI-2010 index. CONCLUSIONS/INTERPRETATION: The small ethnic differences in risk of type 2 diabetes associated with scores of a priori-defined dietary patterns may be due to a different consumption pattern of food components and the fact that the original indexes were not based on diets typical for Asians and Pacific Islanders.

Evaluation of various biomarkers as potential mediators of the association between coffee consumption and incident type 2 diabetes in the EPIC-Potsdam Study.

BACKGROUND: The inverse association between coffee consumption and the risk of type 2 diabetes (T2D) is well established; however, little is known about potential mediators of this association. OBJECTIVE: We aimed to investigate the association between coffee consumption and diabetes-related biomarkers and their potential role as mediators of the association between coffee consumption and T2D. DESIGN: We analyzed a case-cohort study (subcohort: n = 1610; verified incident T2D cases: n = 417) nested within the European Prospective Investigation into Cancer and Nutrition-Potsdam study involving 27,548 middle-aged participants. Habitual coffee consumption was assessed with a validated, semiquantitative food-frequency questionnaire. We evaluated the association between coffee consumption and several T2D-related biomarkers, such as liver markers (reflected by γ-glutamyltransferase, fetuin-A, and sex hormone-binding globulin), markers of dyslipidemia (high-density lipoprotein cholesterol and triglycerides), inflammation [C-reactive protein (CRP)], an adipokine (adiponectin), and metabolites, stratified by sex. RESULTS: Coffee consumption was inversely associated with diacyl-phosphatidylcholine C32:1 in both sexes and with phenylalanine in men, as well as positively associated with acyl-alkyl-phosphatidylcholines C34:3, C40:6, and C42:5 in women. Furthermore, coffee consumption was inversely associated with fetuin-A (P-trend = 0.06) and CRP in women and γ-glutamyltransferase and triglycerides in men. Coffee consumption tended to be inversely associated with T2D risk in both sexes, reaching significance only in men [HR (95% CI): women: ≥4 compared with >0 to <2 cups coffee/d: 0.78 (0.46, 1.33); men: ≥5 compared with >0 to <2 cups coffee/d: 0.40 (0.19, 0.81)]. The association between coffee consumption and T2D risk in men was slightly reduced after adjustment for phenylalanine or lipid markers. CONCLUSIONS: Coffee consumption was inversely associated with a diacyl-phosphatidylcholine and liver markers in both sexes and positively associated with certain acyl-alkyl-phosphatidylcholines in women. Furthermore, coffee consumption showed an inverse trend with CRP in women and with triglycerides and phenylalanine in men. However, these markers explained only to a small extent the inverse association between long-term coffee consumption and T2D risk.

Breast-feeding and maternal risk of type 2 diabetes: a prospective study and meta-analysis.

AIMS/HYPOTHESIS: We aimed to examine the association between breast-feeding and maternal risk of type 2 diabetes and to investigate whether this association is mediated by anthropometric and biochemical factors. METHODS: A case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study between 1994 and 2005 including 1,262 childbearing women (1,059 in a random sub-cohort and 203 incident cases) mainly aged between 35 and 64 years at baseline was applied. Self-reported lifetime duration of breast-feeding was assessed by questionnaire. Blood samples were used for biomarker measurement (HDL-cholesterol, triacylglycerols, C-reactive protein, fetuin-A, γ-glutamyltransferase, adiponectin). A systematic literature search and meta-analysis was conducted of prospective cohort studies investigating breast-feeding and risk of type 2 diabetes. RESULTS: The HR for each additional 6 months of breast-feeding was 0.73 (95% CI 0.56, 0.94) in EPIC-Potsdam. Meta-analysis of three previous prospective studies and the current study revealed an inverse association between breast-feeding duration and risk of diabetes (pooled HR for lifetime breast-feeding duration of 6-11 months compared with no breast-feeding 0.89; 95% CI 0.82, 0.97). Adjustment for BMI and waist circumference attenuated the association (HR per six additional months in EPIC-Potsdam 0.80; 95% CI 0.61, 1.04). Further controlling for potentially mediating biomarkers largely explained this association (HR 0.89; 95% CI 0.68, 1.16). CONCLUSIONS/INTERPRETATION: Longer duration of breast-feeding may be related to a lower risk of diabetes. This potentially protective effect seems to be reflected by a more favourable metabolic profile; however, the role of body weight as a mediator or confounder remains uncertain.