Data are conflicting about the effects of alcohol intake on kidney function. This population-based study investigated associations of alcohol intake with kidney function and mortality. The study cohort included adult participants in Exam-1, Exam-2 (6-year follow-up), and Exam-3 (20-year follow-up) of the Gubbio study.
Kidney function was evaluated as estimated glomerular filtration rate (eGFR, CKD-Epi equation, mL/min x 1.73 m(2)). Daily habitual alcohol intake was assessed by questionnaires. Wine intake accounted for >94% of total alcohol intake at all exams. Alcohol intake significantly tracked over time (R > 0.66, p < 0.001). Alcohol intake distribution was skewed at all exams (skewness > 2) and was divided into four strata for analyses (g/day = 0, 1-24, 25-48, and >48). Strata of alcohol intake differed substantially for lab markers of alcohol intake (p < 0.001).
In multivariable regression, strata of alcohol intake related cross-sectionally to eGFR at all exams (Exam-1: B = 1.70, p < 0.001; Exam-2: B = 1.03, p < 0.001; Exam-3: B = 0.55, p = 0.010) and related longitudinally to less negative eGFR change from Exam-1 to Exam-2 (B = 0.133, p = 0.002) and from Exam-2 to Exam-3 (B = 0.065, p = 0.004). In multivariable Cox models, compared to no intake, intakes > 24 g/day were not associated with different mortality while an intake of 1-24 g/day was associated with lower mortality in the whole cohort (HR = 0.77, p = 0.003) and in the subgroup with eGFR < 60 mL/min x 1.73 m(2) (HR = 0.69, p = 0.033). These data indicate a positive independent association of alcohol intake with kidney function not due to a mortality-related selection.
Findings from earlier studies on the association between adherence to a Mediterranean diet and risk of overweight/obesity were inconsistent. We summarized cohort studies investigating the association between the Mediterranean diet and risk of overweight and/or obesity and weight change in adults. A systematic search of PubMed, Scopus, ISI Web of Science, and Google Scholar was conducted up to May 2021.
Prospective cohorts that examined the Mediterranean diet adherence in adults as the exposure, and overweight and/or obesity or weight change as the outcomes, and reported RRs or beta coefficients and 95% CIs as the effect sizes were included. Seven prospective cohort studies were included of which 6 studies (with 244,678 adult participants) reported the risk of overweight and/or obesity, and 4 cohorts (with 436,617 participants) reported the weight change (3 cohorts reported both overweight and/or obesity risk and weight change).
Combining 15 effect sizes from 6 cohorts revealed that greater adherence to the Mediterranean diet was significantly associated with a 9% decreased risk of overweight and/or obesity (RR: 0.91; 95% CI: 0.88, 0.94; I2 = 44.7%; PQ-test = 0.031). This association was significant in the case of studies investigating combined overweight and obesity (RR: 0.92; 95% CI: 0.88, 0.96; I2 = 29.4%; PQ-test = 0.166), but not for studies that reported on obesity (RR: 0.68; 95% CI: 0.43, 1.10, I2 = 50.6%, PQ-test = 0.132).
Linear dose-response analysis of 6 studies showed a 2% decreased risk of overweight and/or obesity for 1 additional Mediterranean diet score (RR: 0.98; 95% CI: 0.96, 0.99). Each unit increase in the Mediterranean diet score was associated with 0.04 kg less weight gain over 5 y (-0.04 kg; 95% CI: -0.07, -0.02 kg; 13 effect sizes from 4 cohorts).
In conclusion, Mediterranean diet adherence is inversely associated with risk of overweight and/or obesity as well as 5-y weight gain and thus has practical importance for public health.
IMPORTANCE: Observational studies have consistently proposed cardiovascular benefits associated with light alcohol consumption, while recent genetic analyses (ie, mendelian randomization studies) have suggested a possible causal link between alcohol intake and increased risk of cardiovascular disease. However, traditional approaches to genetic epidemiology assume a linear association and thus have not fully evaluated dose-response estimates of risk across different levels of alcohol intake.
OBJECTIVES: To assess the association of habitual alcohol intake with cardiovascular disease risk and to evaluate the direction and relative magnitude of cardiovascular risk associated with different amounts of alcohol consumption.
DESIGN, SETTING, and PARTICIPANTS: This cohort study used the UK Biobank (2006-2010, follow-up until 2016) to examine confounding in epidemiologic associations between alcohol intake and cardiovascular diseases. Using both traditional (ie, linear) and nonlinear mendelian randomization, potential associations between alcohol consumption and cardiovascular diseases (eg, hypertension and coronary artery disease) as well as corresponding association shapes were assessed. Data analysis was conducted from July 2019 to January 2022.
EXPOSURES: Genetic predisposition to alcohol intake.
MAIN OUTCOMES AND MEASURES: The association between alcohol consumption and cardiovascular diseases, including hypertension, coronary artery disease, myocardial infarction, stroke, heart failure, and atrial fibrillation.
RESULTS: This study included 371463 participants (mean [SD] age, 57.0 [7.9] years; 172400 [46%] men), who consumed a mean (SD) 9.2 (10.6) standard drinks per week. Overall, 121708 participants (33%) had hypertension. Light to moderate alcohol consumption was associated with healthier lifestyle factors, adjustment for which attenuated the cardioprotective epidemiologic associations with modest intake. In linear mendelian randomization analyses, a 1-SD increase in genetically predicted alcohol consumption was associated with 1.3-fold (95% CI, 1.2-1.4) higher risk of hypertension (P < .001) and 1.4-fold (95% CI, 1.1-1.8) higher risk of coronary artery disease (P = .006). Nonlinear mendelian randomization analyses suggested nonlinear associations between alcohol consumption and both hypertension and coronary artery disease: light alcohol intake was associated with minimal increases in cardiovascular risk, whereas heavier consumption was associated with exponential increases in risk of both clinical and subclinical cardiovascular disease.
CONCLUSIONS and RELEVANCE: In this cohort study, coincident, favorable lifestyle factors attenuated the observational benefits of modest alcohol intake. Genetic epidemiology suggested that alcohol consumption of all amounts was associated with increased cardiovascular risk, but marked risk differences exist across levels of intake, including those accepted by current national guidelines.