Cross-sectional association between total level and type of alcohol consumption and glycosylated haemoglobin level: the EPIC-Norfolk Study

Alcohol Consumption and Cardiovascular Disease: A Narrative Review of Evolving Perspectives and Long-Term Implications

Cardiovascular illnesses remain the primary cause of death, accounting for at least 17.9 million fatalities per year and posing a significant public health problem because of its extensive predominance and effect on healthcare systems. The etiology of cardiovascular disease is complex and involves several environmental and lifestyle factors. Alcohol use is a highly important determinant because of its dual-edged effect on cardiovascular health. Multiple studies indicate that moderate alcohol consumption may have certain advantages, such as slight enhancements in lipid profiles. Conversely, excessive alcohol intake is associated with serious negative consequences, including cardiomyopathy, hypertension, arrhythmias, and even mortality. The aim of this study is to provide a comprehensive analysis of the several effects of alcohol on cardiovascular health and their understanding within the medical field over time. It uses an interpretative narrative review methodology and analyzes studies that focus on genetic risk factors, gender differences, and shifts in paradigms in recent years. This article highlights the need for obtaining a thorough understanding of the effects of alcohol on cardiovascular health to support public health guidelines and clinical practice, and it underscores the significance of including alcohol consumption into the broader context of cardiovascular risk management and identifies important subjects for further study.

Phenotypic and lifestyle determinants of HbA1c in the general population-The Hoorn Study

Aim

To investigate the relative contribution of phenotypic and lifestyle factors to HbA_1c, independent of fasting plasma glucose (FPG) and 2h post-load glucose (2hPG), in the general population.

Methods

The study populations included 2309 participants without known diabetes from the first wave of the Hoorn Study (1989) and 2619 from the second wave (2006). Multivariate linear regression models were used to analyze the relationship between potential determinants and HbA_1c in addition to FPG and 2hPG. The multivariate model was derived in the first wave of the Hoorn Study, and replicated in the second wave.

Results

In both cohorts, independent of FPG and 2hPG, higher age, female sex, larger waist circumference, and smoking were associated with a higher HbA_1c level. Larger hip circumference, higher BMI, higher alcohol consumption and vitamin C intake were associated with a lower HbA_1c level. FPG and 2hPG together explained 41.0% (first wave) and 53.0% (second wave) of the total variance in HbA_1c. The combination of phenotypic and lifestyle determinants additionally explained 5.7% (first wave) and 3.9% (second wave).

Conclusions

This study suggests that, independent of glucose, phenotypic and lifestyle factors are associated with HbA_1c, but the contribution is relatively small. These findings contribute to a better understanding of the low correlation between glucose levels and HbA_1c in the general population.

Beer, wine and distilled spirits in Ontario: A comparison of recent policies, regulations and practices

Aims

There is a long-standing discussion about whether some beverages are more likely to be linked with high-risk drinking and damage than others, and implications for beverage specific alcohol policies. While the evidence is inconclusive, when controlling for individual consumption, some studies have shown elevated risks by beverage type. This paper examines the situation in Ontario, Canada, from 1995 to present (2011) on several dimensions in order to assess the differences by beverage and their rationale with a specific focus on the most recent policie.

Methods

This paper draws on archival consumption statistics, taxation and pricing arrangements, and retailing and marketing practices.

Results

Off-premise sales, which represent an estimated 75% of ethanol, involve several channels: stores controlled by the Liquor Control Board (LCBO) – which sell all spirits, imported and domestic wines, and beer products; the Beer Store network which sell all beers; and Ontario winery stores – which sell Ontario wines. In LCBO stores Ontario wines are more prominently displayed than other beverages, and extensive print advertising tends to feature wine over beer and spirits. There are also differences by beverage in terms of taxation and price. The taxes on higher alcohol content beverage types account for a higher portion of the retail price than taxes on lower alcohol content beverage types. Furthermore, minimum price regulations allow for differential minimum pricing per standard drink [17.05 ml ethanol] across beverage types.

Conclusions

The apparent rationale for these arrangements is not primarily that of favouring lighter-strength beverages in order to reduce harm, but rather to accommodate long-standing vested interests which are primarily financially based.

Association between Alcohol Intake and Hemoglobin A1c in the Korean Adults: The 2011-2013 Korea National Health and Nutrition Examination Survey

BACKGROUND

Although alcohol consumption is commonly encountered in clinical practice, few studies have investigated the clinical significance of alcohol intake on the use of the hemoglobin A1c (HbA1c) level.

OBJECTIVES

This study was performed to investigate the association between alcohol intake and HbA1c level in the general population.

METHODS

Among the 24,594 participants who participated in the 2011-2013 Korea National Health and Nutrition Examination Survey (KNHANES), 12,923 participants were analyzed in this study. We excluded diabetic patients currently taking antidiabetes medication. We compared the HbA1c level and proportions of patients with an HbA1c level of ≥5.7%, ≥6.1%, and ≥6.5% according to the fasting plasma glucose (FPG) concentration range and the amount of alcohol intake. The average amounts of daily alcohol intake were categorized into three groups: 0 g/day, <30 g/day, ≥30 g/day.

RESULTS

The mean HbA1c level was 5.65%, and the mean FPG concentration was 95.3 mg/dl. The percentages of patients with an HbA1c level of ≥5.7%, ≥6.1%, and ≥6.5% were 42.6%, 13.4%, and 4.5%, respectively. The average amount of alcohol intake was 12.3 g/day. The percentages of subjects with alcohol intake 0, <30, and ≥ 30 g/day were 16.5%, 69.7%, and 13.8%, respectively. There was a significant positive relationship between alcohol intake and FPG concentration (P < 0.001), the prevalence of impaired fasting glucose (P < 0.001), and the prevalence of diabetes (P < 0.001). However, there was no significant relationship between the alcohol intake and HbA1c level. Overall, the adjusted HbA1c levels decreased across alcohol intake (5.70% ± 0.01%, 5.66% ± 0.01%, and 5.55% ± 0.01%) after adjustment for confounding factors such as age, sex, FPG concentration, college graduation, smoking history, presence of hypertension, waist circumference, serum total cholesterol concentration, serum high-density lipoprotein cholesterol concentration, serum triglyceride concentration, presence of anemia, serum white blood cell count, and serum alanine aminotransferase concentration (P < 0.001). The adjusted proportions (%) of patients with an HbA1c level of ≥5.7% (P < 0.001), ≥6.1% (P < 0.001), and ≥6.5% (P < 0.001) showed significant negative trends across alcohol intake after adjustment for confounders. Logistic regression analyses showed that, when using the group that abstained as the control, the group that consumed ≥ 30g/day was negatively associated with the risk of an HbA1c level of ≥5.7% (P < 0.001), ≥6.1% (P < 0.001), and ≥6.5% (P < 0.001), using the above-mentioned variables as covariates.

CONCLUSIONS

Higher alcohol intake was associated with lower HbA1c levels, even after adjusting for confounding factors, including the FPG concentration, in this nationally representative sample of Korean adults. These results suggest that excessive drinking shifts the HbA1c level downward, which might complicate use of the HbA1c level for the diagnosis of diabetes or prediabetes.

Alcohol consumption reduces HbA1c and glycated albumin concentrations but not 1,5-anhydroglucitol

Background The effect of alcohol consumption on glycaemic control indicators is not well known. In this study, we studied the effect of alcohol consumption on the plasma glucose and glycaemic control indicators in non-diabetic men. Methods The study enrolled 300 non-diabetic men who received a complete medical checkup (age: 52.8 ± 6.5 years, body mass index: 24.4 ± 2.8 kg/m²). The subjects were divided into four groups by the amount of alcohol consumed, and the plasma glucose, HbA1c, glycated albumin (GA) and 1,5-anhydroglucitol (1,5-AG) concentrations of the groups were compared. Results As the level of alcohol consumption increased, significantly high concentrations of fasting plasma glucose (FPG) were observed, and the oral glucose tolerance test 2-h plasma glucose concentrations tended to rise. While no significant effect of alcohol consumption on HbA1c, 1,5-AG, and the 1,5-AG/FPG ratio was observed, the HbA1c/FPG ratio, GA and the GA/FPG ratio exhibited significantly low values as the level of alcohol consumption increased. In stepwise multivariate regression analysis, alcohol consumption was a significant negative independent variable for HbA1c and GA, but not for 1,5-AG. Conclusions As the level of alcohol consumption increased, the plasma glucose concentrations rose, but the HbA1c and GA concentrations were lower compared with the plasma glucose concentrations. These findings suggest that alcohol consumption may reduce HbA1c and GA concentrations, but not 1,5-AG.

Association between Self-Reported Smoking and Hemoglobin A1c in a Korean Population without Diabetes: The 2011-2012 Korean National Health and Nutrition Examination Survey

Background

Several Western studies have revealed that among non-diabetics, glycosylated hemoglobin A1c (HbA1c) levels are higher in smokers than non-smokers. While studies conducted in Western populations consistently support this association, a recent meta-analysis reported that studies carried out in non-Western populations, including studies of Chinese, Egyptian, and Japanese-Americans, did not detect any significant differences in HbA1c levels between smokers and non-smokers.

Objectives

We assessed the association between smoking habits and HbA1c levels in the general Korean adult population using data from the Korean National Health and Nutrition Examination Survey (KNHANES) performed in 2011–2012.

Methods

A total of 10,241 participants (weighted n=33,946,561 including 16,769,320 men and 17,177,241 women) without diabetes were divided into four categories according to their smoking habits: never smokers (unweighted n/ weighted n= 6,349/19,105,564), ex-smokers (unweighted n/ weighted n= 1,912/6,207,144), current light smokers (<15 cigarettes per day, unweighted n/ weighted n=1,205/5,130,073), and current heavy smokers (≥15 cigarettes per day, unweighted n/ weighted n=775/3,503,781).

Results

In age- and gender-adjusted comparisons, the HbA1c levels of each group were 5.52 ± 0.01% in non-smokers, 5.49 ± 0.01% in ex-smokers, 5.53 ± 0.01% in light smokers, and 5.61 ± 0.02% in heavy smokers. HbA1c levels were significantly higher in light smokers than in ex-smokers (p = 0.033), and in heavy smokers compared with light smokers (p < 0.001). The significant differences remained after adjusting for age, gender, fasting plasma glucose, heavy alcohol drinking, hematocrit, college graduation, and waist circumference. Linear regression analyses for HbA1c using the above-mentioned variables as covariates revealed that a significant association between current smoking and HbA1c (coefficient 0.021, 95% CI 0.003–0.039, p = 0.019).

Conclusions

Current smoking was independently associated with higher HbA1c levels in a cigarette exposure-dependent manner in a representative population of Korean non-diabetic adults. In this study, we have observed an association between smoking status and HbA1c levels in non-diabetics drawn from a non-Western population, consistent with previous findings in Western populations.

The effect of alcohol consumption on insulin sensitivity and glycemic status: a systematic review and meta-analysis of intervention studies

OBJECTIVE

Moderate alcohol consumption is associated with a reduced risk of type 2 diabetes. This reduced risk might be explained by improved insulin sensitivity or improved glycemic status, but results of intervention studies on this relation are inconsistent. The purpose of this study was to conduct a systematic review and meta-analysis of intervention studies investigating the effect of alcohol consumption on insulin sensitivity and glycemic status.

RESEARCH DESIGN AND METHODS

PubMed and Embase were searched up to August 2014. Intervention studies on the effect of alcohol consumption on biological markers of insulin sensitivity or glycemic status of at least 2 weeks' duration were included. Investigators extracted data on study characteristics, outcome measures, and methodological quality.

RESULTS

Fourteen intervention studies were included in a meta-analysis of six glycemic end points. Alcohol consumption did not influence estimated insulin sensitivity (standardized mean difference [SMD] 0.08 [-0.09 to 0.24]) or fasting glucose (SMD 0.07 [-0.11 to 0.24]) but reduced HbA1c (SMD -0.62 [-1.01 to -0.23]) and fasting insulin concentrations (SMD -0.19 [-0.35 to -0.02]) compared with the control condition. Alcohol consumption among women reduced fasting insulin (SMD -0.23 [-0.41 to -0.04]) and tended to improve insulin sensitivity (SMD 0.16 [-0.04 to 0.37]) but not among men. Results were similar after excluding studies with high alcohol dosages (>40 g/day) and were not influenced by dosage and duration of the intervention.

CONCLUSIONS

Although the studies had small sample sizes and were of short duration, the current evidence suggests that moderate alcohol consumption may decrease fasting insulin and HbA1c concentrations among nondiabetic subjects. Alcohol consumption might improve insulin sensitivity among women but did not do so overall.

Determinants of HbA1c in nondiabetic Dutch adults: genetic loci and clinical and lifestyle parameters, and their interactions in the Lifelines Cohort Study

OBJECTIVES

Glycated haemoglobin (HbA1c) is associated with cardiovascular disease risk in individuals without diabetes, and its use has been recommended for diagnosing diabetes. Therefore, it is important to gain further understanding of the determinants of HbA1c. The aim of this study was to investigate the effects of genetic loci and clinical and lifestyle parameters, and their interactions, on HbA1c in nondiabetic adults.

DESIGN

Population-based cohort study.

SETTING

Three northern provinces of the Netherlands.

SUBJECTS

A total of 2921 nondiabetic adults participating in the population-based LifeLines Cohort Study.

MEASUREMENTS

Body mass index (BMI), waist circumference, HbA1c, fasting plasma glucose (FPG) and erythrocyte indices were measured. Data on current smoking and alcohol consumption were collected through questionnaires. Genome-wide genotyping was performed, and 12 previously identified single-nucleotide polymorphisms (SNPs) were selected for replication and categorized as 'glycaemic' and 'nonglycaemic' SNPs according to their presumed mechanism(s) of action on HbA1c. Genetic risk scores (GRSs) were calculated as the sum of the weighted effect of HbA1c-increasing alleles.

RESULTS

Age, gender, BMI, FPG, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, current smoking and alcohol consumption were independent predictors of HbA1c, together explaining 26.2% of the variance in HbA1c, with FPG contributing 10.9%. We replicated three of the previously identified SNPs and the GRSs were also found to be independently associated with HbA1c. We found a smaller effect of the 'nonglycaemic GRS' in females compared with males and an attenuation of the effect of the GRS of all 12 SNPs with increasing BMI.

CONCLUSIONS

Our results suggest that a substantial portion of HbA1c is determined by nonglycaemic factors. This should be taken into account when considering the use of HbA1c as a diagnostic test for diabetes.

Increased body mass index modifies associations between alcohol intake and blood cholesterol profile

BACKGROUND AND OBJECTIVES

Habitual alcohol drinking influences blood cholesterol profile, and dyslipidaemia often accompanies obesity. The aim of this study was to determine whether obesity modifies relationships between alcohol intake and blood cholesterol profile.

METHODS

  Japanese men aged 35-60 years (n = 23 834) were divided into two groups by body mass index (BMI) (normal BMI: ≥ 18·5 and < 25 kg/m(2) ; high BMI: ≥ 25 kg/m(2) ) and were further divided into four subgroups by alcohol intake [non-, light (< 22 g ethanol/day), heavy (≥ 22 and < 44 g ethanol/day) and very heavy (≥ 44 g ethanol/day) drinkers]. Relationships of alcohol intake with serum LDL cholesterol, HDL cholesterol and LDL/HDL ratio were investigated.

RESULTS

Both in the subject groups with normal and high BMI, alcohol intake was associated with lower risks of high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio, and these risks tended to decrease as alcohol intake increased. The odds ratios vs. nondrinkers for high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio tended to be lower in the normal BMI group than in the high BMI group. Significant interactions between alcohol drinking and BMI for high LDL cholesterol, low HDL cholesterol and high LDL/HDL ratio were found in all of the drinker subgroups except for the interaction for high LDL cholesterol in light drinkers.

CONCLUSIONS

High BMI status is suggested to attenuate the associations of alcohol intake with lower LDL cholesterol, higher HDL cholesterol and lower LDL/HDL ratio.

Obesity-independent inverse association between regular alcohol consumption and hemoglobin A(1C)

OBJECTIVE

The aim of this study was to determine whether obesity influences relationships between habitual alcohol drinking and hemoglobin A(1C) (HbA(1C)) level.

METHODS

Japanese men (35-70 years old, n = 24858) were divided into non-, light (<22 g ethanol/day), moderate (≥22 and <44 g ethanol/day), and heavy (≥44 g ethanol/day) drinkers. Relationships of alcohol with HbA(1C) were investigated in overall subjects and subjects of quartile groups for degree of obesity.

RESULTS

HbA(1C) tended to be higher as quartiles of BMI and waist-to-height ratio increased. HbA(1C) was significantly lower in light, moderate and heavy drinkers than in nondrinkers. These associations in overall subjects were also found in all of the quartiles of BMI and waist-to-height ratio, except for light drinkers in the 3rd and 4th quartiles of BMI and the 4th quartile of waist-to-height ratio. Odds ratios versus nondrinkers for high HbA(1C) were significantly lower than a reference level of 1.0 in all drinker groups, and these associations were not altered after adjustment for age, history of smoking, and BMI or waist-to-height ratio.

CONCLUSION

The results suggest that alcohol consumption is associated with lower HbA(1C) level independent of degree of obesity.

Association between alcohol drinking and metabolic syndrome in Japanese male workers with diabetes mellitus

AIM

Results of previous studies on the relationship between habitual alcohol drinking and metabolic syndrome in a general population are not consistent, and this relationship in patients with diabetes is unknown. The aim of this study was to clarify the relationship of alcohol consumption with metabolic syndrome in patients with diabetes.

METHODS

Japanese male workers with diabetes (n = 1960) were divided into non-, light (< 22 g ethanol/day), heavy (≥ 22 and < 44 g ethanol/day) and very heavy (≥ 44 g ethanol/day) drinkers. Relationships of alcohol consumption with visceral obesity evaluated by waist circumference, high blood pressure, dyslipidemia (high triglycerides and/or low HDL cholesterol), hyperglycemia, and metabolic syndrome (3 or more of these risk factors by the NCEP-ATP III criteria) were investigated.

RESULTS

Odds ratio vs. nondrinkers for high blood pressure was significantly high in all drinker groups, while odds ratio vs. nondrinkers for low HDL cholesterol was significantly low in all drinker groups. Odds ratio vs. nondrinkers for high triglycerides was significantly low in light drinkers and was significantly high in very heavy drinkers. Odds ratio vs. the nondrinker group for large waist circumference was not significant in any drinker groups. Odds ratio vs. nondrinkers for metabolic syndrome was significantly high in very heavy drinkers but was not significant in light and heavy drinkers.

CONCLUSION

Excessive alcohol intake is associated with a higher risk for metabolic syndrome through elevations of blood pressure and triglycerides in Japanese male patients with diabetes.

Alcohol consumption and the risk of coronary heart disease in postmenopausal women with diabetes: Women's Health Initiative Observational Study

BACKGROUND

Although several observational studies have consistently reported an inverse association between moderate alcohol consumption and risk of coronary heart disease (CHD), it is yet not well established if this association also exists among people with type 2 diabetes. The aim of this study is to evaluate the association between the frequency and quantity of alcohol intake and the risk of developing CHD among postmenopausal women with diabetes.

METHODS

We conducted a prospective cohort study, which included 3,198 women with self-reported diabetes and without any history of cardiovascular disease at baseline, in the Women's Health Initiative Observational Study. Alcohol intake was assessed by a semiquantitative food frequency questionnaire. The primary outcome of this study was CHD, which was validated by medical record review. Cox proportional hazards regression was used to estimate the hazard ratio (HR) for the association of alcohol intake and risk of incident CHD while adjusting for several potential confounders.

RESULTS

During the 22,546 person-years of follow-up, there were 336 incident cases of CHD. Both frequency and quantity of alcohol intake were inversely associated with the risk of developing CHD. Compared to nondrinkers, the multivariable HRs across categories of frequency of alcohol consumption (<or=0.5, 0.5-2 and >or=2 drinks/week) were 0.89 (95% confidence intervals [CI]: 0.63, 1.26), 0.84 (95% CI: 0.56, 1.25) and 0.65 (95% CI: 0.43, 0.99), respectively (p for trend: 0.04). This association did not appear to differ based on the type of the alcoholic beverage consumed.

CONCLUSIONS

Moderate alcohol consumption of postmenopausal women with type 2 diabetes may have a benefit on CHD similar to that seen in postmenopausal nondiabetic women. The potential risks of alcohol on noncardiac outcomes may need consideration when recommending alcohol to women with diabetes.

Diet and glycosylated haemoglobin in the 1946 British birth cohort

OBJECTIVES

Raised glycosylated haemoglobin (HbA(1c)) concentration is a recognized risk factor for diabetes, the incidence of which is rising worldwide. The intake of certain foods has been related to HbA(1c) concentration. The aim of this study was to investigate whether nutrient intake, sourced by these foods, was predictive of raised glycosylated haemoglobin (HbA(1c)) concentration in a British cohort.

SUBJECTS

The subjects were 495 men and 570 women who were members of the Medical Research Council National Survey of Health and Development, 1946 birth cohort.Diet was assessed from 5-day records in 1982, 1989 and 1999. HbA(1c) was measured in blood samples collected in 1999. Individuals in whom concentration of HbA(1c) was > or =6.3% were identified as being 'at risk' and their nutrient intake was compared with those whose concentration of HbA(1c) was within the normal range (< or =6.2%).

RESULTS

Lower intakes of protein, carbohydrate, non-starch polysaccharide, iron, folate, vitamin B(12) and a higher percentage energy from fat in 1989 were significantly predictive of high HbA(1c) status in 1999. In 1999, there were no nutrient intakes that were predictive of HbA(1c) status. Global tests of whether the intakes of energy, carbohydrate, sodium, iron, riboflavin and vitamin B(12) at all three time points were related to HbA(1c) status in 1999, were significant.

CONCLUSION

An increased intake of energy, carbohydrate, sodium, iron, riboflavin and vitamin B(12) over 10 years was predictive of raised HbA(1c) status. Increased energy intake may have resulted in increase in body weight, which is a risk factor for diabetes.

The relationship between alcohol consumption and glycemic control among patients with diabetes: the Kaiser Permanente Northern California Diabetes Registry

BACKGROUND

Alcohol consumption is a common behavior. Little is known about the relationship between alcohol consumption and glycemic control among people with diabetes.

OBJECTIVE

To evaluate the association between alcohol consumption and glycemic control.

DESIGN

Survey follow-up study, 1994-1997, among Kaiser Permanente Northern California members.

PATIENTS

38,564 adult diabetes patients.

MEASUREMENTS

Self-reported alcohol consumption, and hemoglobin A1C (A1C), assessed within 1 year of survey date. Linear regression of A1C by alcohol consumption was performed, adjusted for sociodemographic variables, clinical variables, and diabetes disease severity. Least squares means estimates were derived.

RESULTS

In multivariate-adjusted models, A1C values were 8.88 (lifetime abstainers), 8.79 (former drinkers), 8.90 (<0.1 drink/day), 8.71 (0.1-0.9 drink/day), 8.51 (1-1.9 drinks/day), 8.39 (2-2.9 drinks/day), and 8.47 (>/=3 drinks/day). Alcohol consumption was linearly (p < 0.001) and inversely (p = 0.001) associated with A1C among diabetes patients.

CONCLUSIONS

Alcohol consumption is inversely associated with glycemic control among diabetes patients. This supports current clinical guidelines for moderate levels of alcohol consumption among diabetes patients. As glycemic control affects incidence of complications of diabetes, the lower A1C levels associated with moderate alcohol consumption may translate into lower risk for complications.

Alcohol intake, consumption pattern and beverage type, and the risk of Type 2 diabetes

AIMS

To examine associations between amount and frequency of alcohol consumption, and Type 2 diabetes.

METHODS

A prospective study of 36 527 adults aged 40-69 at baseline. Incident cases of Type 2 diabetes were identified by questionnaire 4 years later. Sex-specific logistic regression models, adjusting for country of birth, dietary glycaemic index, energy intake and age, and in a second model body mass index (BMI) and waist-hip ratio (WHR), were used.

RESULTS

Diabetes status was ascertained for 31 422 (86%) participants, and 362 cases identified. Former drinkers had higher risks than lifetime abstainers. Female drinkers had lower risk than lifetime abstainers (ORs < 10 g/day 0.54, 95% CI 0.36-0.82; 10-19.9 g/day 0.57, 0.34-0.94; > or = 20 g/day 0.46, 0.24-0.88, P trend = 0.005). There was no relationship after adjustment for body size. For men, a weak inverse association was observed after adjustment for body size (ORs relative to lifetime abstainers: < 10 g/day 1.56, 0.95-2.55; 10-19.9 g/day 1.21, 0.69-2.10; 20-29.9 g/day 0.80, 0.40-1.60; = 30 g/day 0.86, 0.50-1.58, P trend = 0.036). Wine was the only beverage for which an inverse association was observed. Compared with men who did not drink in the week before baseline, men who drank > or = 210 g over 1-3 days had an increased risk of diabetes (OR 5.21, 1.79-15.19), while the same amount over more days did not increase risk.

CONCLUSIONS

Total alcohol intake was associated with reduced risk only in women. Alcohol from wine was associated with reduced risk of Type 2 diabetes. A high daily intake of alcohol, even on only 1-3 days a week, may increase the risk of diabetes in men.

Glycemic control, atherosclerosis, and risk factors for cardiovascular disease in individuals with diabetes: the atherosclerosis risk in communities study

OBJECTIVE

Glycemic control (HbA(1c) [A1C]) is strongly associated with microvascular disease in individuals with diabetes, but its relation to macrovascular disease and atherosclerosis is less clear. This study examines the relationship between A1C, carotid intima-media thickness (IMT), and traditional cardiovascular risk factors in individuals with diabetes.

RESEARCH DESIGN AND METHODS

A cross-sectional study of 2,060 people with diagnosed and undiagnosed (unrecognized) diabetes in the Atherosclerosis Risk in Communities study was performed.

RESULTS

LDL and HDL cholesterol, plasma triglycerides, and waist-to-hip ratio were significantly associated with A1C after multivariable adjustment. African Americans with undiagnosed and diagnosed diabetes had significantly elevated A1C values compared with whites, even after adjustment for potentially confounding factors. There was a graded association between A1C and carotid IMT. In a fully adjusted model in individuals with undiagnosed diabetes, the odds ratio (OR) of being in the highest quartile of IMT versus the lowest was 2.46 (95% CI 1.16-5.03, comparing the highest quartile of A1C to the lowest). In people with diagnosed diabetes, the comparable OR was 2.62 (1.36-5.06).

CONCLUSIONS

This study identified several important associations between A1C and known risk factors for cardiovascular disease and suggested that A1C is independently related to carotid IMT. Chronically elevated glucose levels may contribute to the development of atherosclerosis in people with diabetes, independent of other risk factors.

The relationship of postprandial glucose to HbA1c

The gold standard for the assessment of the overall glycemic control is the determination of HbA1c. There are, however, insufficient data to determine reliably the relative contribution of fasting and postprandial plasma glucose to HbA1c. Increasing evidence suggests that excessive excursions of postprandial glucose might be important for the development of micro- and macroangiopathic complications. With respect to the treatment options, one important question to be answered is whether premeal, postmeal or fasting plasma glucose, alone or in combination, will be necessary in adjusting the therapy to achieve optimal HbA1c levels while minimizing hypoglycemia. HbA1c is difficult to predict from fasting plasma glucose. There are indications that there is a shift in the relative contribution from postprandial glucose at good to fair HbA1c levels (<7.3% to <9.2%) to fasting plasma glucose at high HbA1c (>9.3%). There is also a better correlation of afternoon and evening plasma glucose with HbA1c than with prebreakfast and prelunch plasma glucose values. Since the definition on how to define postprandial glucose is still a matter of debate and since postprandial glucose depends on the premeal blood glucose level and, on the time of the meal, its size and composition and the therapeutic strategy, the data so far available are inconclusive and the best correlation of HbA1c is with the area under the glucose profiles. Continuous glucose monitoring under daily life conditions will be the key to definitely unravel the relationship among HbA1c and fasting, premeal, postprandial and postabsorptive plasma glucose.

Alcohol intake and insulin resistance. A cross-sectional study

BACKGROUND AND AIM

The development of insulin resistance is a critical step in the pathogenesis of type 2 diabetes. The effect of alcohol intake on insulin sensitivity/resistance is not well defined. The aim of this study was to examine the association between alcohol intake and insulin resistance in a sample of middle-aged men and women with data on a wide range of potential confounding factors, including diet.

METHODS

We performed a cross sectional study involving a group of 1018 men and women, sampled from 17 general practice lists in the South of Ireland, with a response rate of 69%. Participants completed a detailed health and lifestyle questionnaire and a food frequency questionnaire and provided fasting blood samples for analysis of glucose and insulin. Insulin resistance was estimated on the basis of fasting glucose and insulin, using the glucose homeostasis model (HOMA scores). Insulin resistance was defined as the upper quartile of the HOMA scores.

RESULTS

We found evidence of a U-shaped relationship between alcohol intake and insulin resistance fitted as a continuous variable (HOMA scores) with lowest levels in light drinkers (between 0.5 to 0.99 units per day) relative to the other drinking categories. However no significant association between alcohol intake and HOMA score was observed in fully adjusted analyses, including adjustment for dietary saturated fat and fruit and vegetables intake. In logistic regression analysis with insulin resistance (categorical) as the dependent variable, we observed that ex-drinkers were at higher risk of insulin resistance compared to occasional drinkers independently of age, sex, BMI and waist circumference, (OR=2.4, 95% CI, 1.1-5.7, p=0.04). On further adjustment for potential confounders including diet this association was also attenuated and was non-significant.

CONCLUSIONS

The reported effects of alcohol intake on insulin resistance may be confounded by other aspects of lifestyle, especially diet.

Diet composition and the risk of type 2 diabetes: epidemiological and clinical evidence

In the last 10 years nutritional research on diabetes has improved dramatically in terms of both number of studies produced and quality of methodologies employed. Therefore, it is now possible to attempt to provide the evidence on which nutritional recommendations for the prevention of type 2 diabetes could be based. We therefore performed a literature search and, among the papers published in indexed journals, we selected relevant epidemiological (mostly prospective) and controlled intervention studies. Lifestyle factors that have, so far, been consistently associated with increased risk of type 2 diabetes are overweight and physical inactivity. However, recent evidence from epidemiological studies has shown that the risk of type 2 diabetes is also associated with diet composition, particularly with: (1) low fibre intake; (2) a high trans fatty acid intake and a low unsaturated:saturated fat intake ratio; (3) absence of or excess alcohol consumption. All these factors are extremely common in Western populations and therefore the potential impact of any intervention on them is large: indeed, >90 % of the general population has one or more of these risk factors. The ability to correct these behaviours in the population is estimated to reduce the incidence of diabetes by as much as 87 %. Recent intervention studies have shown that type 2 diabetes can be prevented by lifestyle changes aimed at body-weight reduction, increased physical activity and multiple changes in the composition of the diet. Within this context, the average amount of weight loss needed is not large, about 5 % initial weight, which is much less than the weight loss traditionally considered to be clinically significant for prevention of type 2 diabetes. In conclusion, new emphasis on prevention by multiple lifestyle modifications, including moderate changes in the composition of the habitual diet, might limit the dramatic increase in incidence of type 2 diabetes envisaged worldwide.

Nutrient intakes; biochemical and risk indices associated with Type 2 diabetes and glycosylated haemoglobin, in the British National Diet and Nutrition Survey of people aged 65 years and over

AIMS

To characterize nutritional differences between survey participants diagnosed with Type 2 diabetes; those without diabetes, and those with "undiagnosed diabetes" based on glycosylated haemoglobin (HbA(1c)).

SUBJECTS AND METHODS

The 1994/5 British National Diet and Nutrition Survey, of people aged 65 years and over (mean age 78 years), included 73 respondents with diagnosed Type 2 diabetes [mean (sd) HbA(1c) = 7.06 (2.05)%], and 30 with "undiagnosed diabetes" (defined as HbA(1c) > 6.3%; mean (sd) HbA(1c) = 7.40 (1.66)%], among a representative sample of 1038 with anthropometry; 4-day weighed diet; blood and urine status measurements.

RESULTS

The prevalence of Type 2 diabetes (diagnosed + undiagnosed) was 10%. In subjects without diagnosis of diabetes, those with HbA(1c) > 6.3% had on average a significantly higher body weight (73.6 vs. 67.9 kg), higher waist circumference (99.8 vs. 91.8 cm), higher body mass index (28.6 vs. 25.9 kg/m(2)) and higher white cell counts (7.64 vs. 7.09 x 10(9)/l), than those with mean HbA(1c) < or = 6.3%. Diagnosed diabetic subjects had significantly higher energy-adjusted intakes of protein, fibre, vitamins and minerals than those not in this category (P < 0.01). In contrast, those with undiagnosed diabetes (HbA(1c) > 6.3%) were nutritionally "at risk", having low plasma concentrations of lycopene (0.13 vs. 0.24 micromol/l) and high density lipoprotein cholesterol (0.99 vs. 1.27 micromol/l) and a trend towards low vitamin C (24 vs. 36 micromol/l) which was significant (P < 0.01) for men. HbA(1c) was positively correlated with white cell count, plasma fasting triglycerides, plasma alkaline phosphatase and homocysteine (all P < 0.01 overall), being particularly striking amongst men.

CONCLUSIONS

Among older British citizens, those with diagnosed diabetes had healthier nutritional profiles than those undiagnosed with high HbA(1c). Important health-promoting benefits are therefore predicted following early diagnosis and nutritional advice for people with Type 2 diabetes.

Habitual fish consumption and glycated haemoglobin: the EPIC-Norfolk study

OBJECTIVE

To investigate the association between habitual fish consumption and a continuous measure of glycaemia.

DESIGN

Cross-sectional study.

SETTING

EPIC-Norfolk, a population-based cohort study of diet and chronic disease.

SUBJECTS AND METHODS

In all, 4500 men and 5509 women, aged 40-78 y, without self-reported diabetes. Diet was assessed by a semiquantitative food frequency questionnaire, and glycaemia was measured by glycated haemoglobin.

RESULTS

In women only, in analyses adjusted for age, the HbA(1c) level was positively associated with eating fried fish and inversely associated with eating oily fish (b=0.036, 95% confidence interval (CI): 0.0033, 0.069; and b=-0.046, 95% CI:-0.086, -0.0064 respectively). These associations were attenuated by adjustment for family history of diabetes, smoking status and physical activity level, but the association with fried fish remained statistically significant (b=0.033, 95% CI: 0.00056, 0.066). Adjusting for total energy, alcohol, fruit and vegetable intakes resulted in further attenuation and both associations were no longer statistically significant. In men, there was no evidence that HbA(1c) level was associated with fish consumption.

CONCLUSIONS

The study found no evidence of an association between fish consumption and HbA(1c) after taking other lifestyle factors into account.

A cross-sectional study of alcohol consumption patterns and biologic markers of glycemic control among 459 women

OBJECTIVE

Little research has explored associations of drinking patterns with glycemic control, especially among women. Our objective was to determine the relationship of patterns of alcohol consumption-including average daily consumption, weekly frequency of consumption, drinking with meals, and beverage type-with biologic markers of insulin resistance in young women.

RESEARCH DESIGN AND METHODS

This study was cross-sectional in design. The subjects consisted of a stratified random subpopulation of 459 U.S. normal-weight and overweight female nurses, 33-50 years of age, drawn from the Nurses' Health Study II and sampled for distinct drinking patterns. Women provided blood samples and detailed information on dietary and lifestyle factors between 1995 and 1999. The main outcome measures were fasting insulin, C-peptide, and HbA(1c).

RESULTS

Adjusting for age, smoking, physical activity, television watching, BMI, and several dietary factors, average alcohol intake was inversely associated with HbA(1c) (units in percentage of HbA(1c)): 0 g/day (reference = 5.36%), 0.1 to <5.0 g/day (-0.04%), 5.0 to <15.0 g/day (-0.09%), 15.0 to <25.0 g/day (-0.10%), and > or =25.0 g/day (-0.17%) (P value, test for trend <0.001). We found an inverse association of alcohol intake and insulin, but only for women with a BMI > or =25 kg/m(2). Specifically, insulin levels were lowest for episodic drinkers consuming > or =2 drinks per day on 0-3 days per week. Consumption with meals and type of alcoholic beverage did not further influence these results.

CONCLUSIONS

Moderate alcohol consumption of 1-2 drinks per day on a few to several days of the week may have a beneficial glycemic effect, particularly among overweight women.