BACKGROUND: Gamma-glutamyltransferase (GGT) levels in the blood can be a sensitive marker of liver injury but the extent to which they give insight into risk across multiple outcomes in a clinically useful way remains uncertain.
METHODS: Using data from 293,667 UK Biobank participants, the relationship of GGT concentrations to self-reported alcohol intake and adiposity markers were investigated. We next investigated whether GGT predicted liver-related, cardiovascular (CV) or all-cause mortality, and potentially improved CV risk prediction.
FINDINGS: Higher alcohol intake and greater waist circumference (WC) were associated with higher GGT; the association was stronger for alcohol with evidence of a synergistic effect of WC. Higher GGT concentrations were associated with multiple outcomes. Compared to a GGT of 14.5 U/L (lowest decile), values of 48 U/L for women and 60 U/L for men (common upper limits of 'normal') had hazard ratios (HRs) for liver-related mortality of 1.83 (95% CI 1.60-2.11) and 3.25 (95% CI 2.38-4.42) respectively, for CV mortality of 1.21 (95% CI 1.14-1.28) and 1.43 (95% CI 1.27-1.60) and for all-cause mortality of 1.15 (95% CI 1.12-1.18) and 1.31 (95% CI 1.24-1.38). Adding GGT to a risk algorithm for CV mortality reclassified an additional 1.24% (95% CI 0.14-2.34) of participants across a binary 5% 10-year risk threshold.
INTERPRETATION: Our study suggests that a modest elevation in GGT levels should trigger a discussion with the individual to review diet and lifestyle including alcohol intake and consideration of formal liver disease and CV risk assessment if not previously done.
FUNDING: British Heart Foundation Centre of Research Excellence Grant (grant number RE/18/6/34217), NHS Research Scotland (grant number SCAF/15/02), the Medical Research Council (grant number MC_UU_00022/2); and the Scottish Government Chief Scientist Office (grant number SPHSU17).
BACKGROUND: Alcohol intake is widely assumed to contribute to excess body fatness, especially among young men; however, the evidence is inconsistent. We have addressed this research question by investigating associations between reported alcohol consumption and body composition from large representative national surveys in a high alcohol-consuming country with a high obesity prevalence.
METHODS: The present study comprised a secondary analysis of combined cross-sectional nationally representative Scottish Health Surveys (1995-2010). Reported alcohol-drinking frequency was divided into five groups: from 'nonfrequent drinking' (reference) to daily/'almost every day' among 35 837 representative adults [mean (SD) age: 42.7 (12.7) years (range 18-64 years)]. Quantitative alcohol consumption was categorised into seven groups: from '1-7 to >/=50 10 g units per week'. Regression models against measured body mass index (BMI) and waist circumference (WC) were adjusted for age, physical activity, income, smoking, deprivation category and economic status.
RESULTS: Among alcohol-consuming men, heavier drinking (21-28 units per week) was associated with a higher BMI by +1.4 kg m(-2) [95% confidence interval (CI) = 1.38-1.43] and higher WC by +3.4 cm (95% CI = 3.2-3.6) than drinking 1-7 units per week. However, those who reported daily drinking frequency were associated with a lower BMI by -2.45 kg m(-2) (95% CI = -2.4 to -2.5) and lower WC by -3.7 cm (95% CI = -3.3 to -4.0) than those who reported less-frequent drinking. Similar associations were found for women. Most of these associations were restricted to subjects aged >30 years. Unexplained variances in BMI and WC are large.
CONCLUSIONS: Quantitative alcohol consumption and frequency of consumption were positively and inversely associated, respectively, with both BMI and WC among alcohol-consuming adults. Surveys are needed that evaluate both the quantity and frequency of consumption. The lowest BMI and WC were associated with a 'Mediterranean' drinking style (i.e. relatively little, but more frequently)
BACKGROUND: Alcohol intake is widely assumed to contribute to excess body fatness, especially among young men; however, the evidence is inconsistent. We have addressed this research question by investigating associations between reported alcohol consumption and body composition from large representative national surveys in a high alcohol-consuming country with a high obesity prevalence.
METHODS: The present study comprised a secondary analysis of combined cross-sectional nationally representative Scottish Health Surveys (1995-2010). Reported alcohol-drinking frequency was divided into five groups: from 'nonfrequent drinking' (reference) to daily/'almost every day' among 35 837 representative adults [mean (SD) age: 42.7 (12.7) years (range 18-64 years)]. Quantitative alcohol consumption was categorised into seven groups: from '1-7 to >/=50 10 g units per week'. Regression models against measured body mass index (BMI) and waist circumference (WC) were adjusted for age, physical activity, income, smoking, deprivation category and economic status.
RESULTS: Among alcohol-consuming men, heavier drinking (21-28 units per week) was associated with a higher BMI by +1.4 kg m(-2) [95% confidence interval (CI) = 1.38-1.43] and higher WC by +3.4 cm (95% CI = 3.2-3.6) than drinking 1-7 units per week. However, those who reported daily drinking frequency were associated with a lower BMI by -2.45 kg m(-2) (95% CI = -2.4 to -2.5) and lower WC by -3.7 cm (95% CI = -3.3 to -4.0) than those who reported less-frequent drinking. Similar associations were found for women. Most of these associations were restricted to subjects aged >30 years. Unexplained variances in BMI and WC are large.
CONCLUSIONS: Quantitative alcohol consumption and frequency of consumption were positively and inversely associated, respectively, with both BMI and WC among alcohol-consuming adults. Surveys are needed that evaluate both the quantity and frequency of consumption. The lowest BMI and WC were associated with a 'Mediterranean' drinking style (i.e. relatively little, but more frequently)
Low-risk thresholds for alcohol use differ across various national guidelines. To assess the novel WHO risk drinking levels in light of alcohol-sensitive common laboratory tests, we analysed biomarkers of liver status, inflammation and lipid profiles from a population-based survey of individuals classified to abstainers and different WHO risk drinking levels defined in terms of mean alcohol consumption per day. The study included 22,327 participants aged 25-74 years from the National FINRISK Study. Data on alcohol use, health status, diet, body weight and lifestyle (smoking, coffee consumption and physical activity) were recorded from structured interviews. Alcohol data from self-reports covering the past 12 months were used to categorize the participants into subgroups of abstainers and WHO risk drinking categories representing low, moderate, high and very high risk drinkers. Serum liver enzymes (GGT, ALT), C-reactive protein (CRP) and lipid profiles were measured using standard laboratory techniques. Alcohol risk category was roughly linearly related with the occurrence of elevated values for GGT, ALT and CRP. Alcohol drinking also significantly influenced the incidence of abnormalities in serum lipids. Significantly higher odds for abnormal GGT, ALT and altered lipid profiles remained in alcohol drinkers even after adjustment for age, waist circumference, physical inactivity, smoking and coffee consumption. A more systematic use of laboratory tests during treatment of individuals classified to WHO risk drinking categories may improve the assessment of alcohol-related health risks. Follow-ups of biomarker responses may also prove to be useful in health interventions aimed at reducing alcohol consumption.