Liver enzymes and incident diabetes in China: a prospective analysis of 10 764 participants in the Guangzhou Biobank Cohort Study

Associations of retinal microvascular alterations with diabetes mellitus: an OCTA-based cross-sectional study

BACKGROUND

Diabetes, a health crisis afflicting millions worldwide, is increasing rapidly in prevalence. The microvascular complications triggered by diabetes have emerged as the principal cause of renal disease and blindness. The retinal microvascular network may be sensitive to early systemic vascular structural and functional changes. Therefore, this research endeavored to discern the systemic determinants influencing the retinal microvascular network in patients with and without diabetes.

METHODS

The Kailuan Eye Study is a cross-sectional study based on the community-based cohort Kailuan Study. Participants underwent optical coherence tomography angiography (OCTA) (Zeiss Cirrus 5000; Carl Zeiss Meditec) and comprehensive systemic examination. Metrics such as perfusion density (PD), vascular density (VD), foveal avascular zone (FAZ) parameters of the superficial capillary plexus (SCP) in the macula were assessed.

RESULTS

This study included 860 eligible participants (average age = 62.75 ± 6.52 years; 21.9% female), of which 449 were diabetics. People with diabetes had diminished PD and VD in the entire macular and parafoveal regions compared to people without diabetes. Reduced PD in the whole macular region was correlated with higher fasting plasma glucose (FPG, mmol/L) concentration (Beta = -0.19, 95% CI = -0.42 to -0.36, P < 0.001), longer axial length (AL, mm) (Beta = -0.13, 95%CI = -0.48 to -0.25, P = 0.002), and elevated heart rate (Beta = -0.10, 95%CI = -0.14 to -0.19, P = 0.014), after adjusting for younger age (Beta = -0.18, 95%CI = -0.24 to -0.35, P < 0.001), consistent with VD of the whole macular region. A higher FPG level was significantly correlated with lower SCP density of both PD and VD in the macular and parafoveal region (P < 0.05 for all), as well as increased systolic blood pressure and low-density lipoprotein cholesterol concentration (P < 0.01 for all).

CONCLUSIONS

In this large-sample cross-sectional study, OCTA evaluation revealed that high prevalence of diabetes and elevated FPG levels were correlated with reduced retinal VD and PD. Hypertension and hyperlipidemia are important risk factors for the development of atherosclerotic cardiovascular disease but have no significant effect on retinal microvascular abnormalities.

Association of adverse childhood experiences with anemia in older Chinese: Guangzhou Biobank Cohort Study

To examine the association of adverse childhood experiences (ACEs) with anemia among older people. 24,116 participants aged 50 years or above were recruited. Multivariable linear and logistic regression was used to assess the associations of self-reported ACEs number with hemoglobin concentrations (g/dL) and presence of anemia. Older individuals with two or more ACEs, versus no ACEs, showed lower hemoglobin concentrations (β =  - 0.08 g/dL, 95% confidence intervals (CI) - 0.12 to - 0.03) and higher odds of anemia (odds ratio = 1.26, 95% CI 1.01-1.59). A more pronounced association between ACEs and anemia in the lower education group was found, while the association became non-significant in those with higher education (P for ACEs-education interaction = 0.02). ACEs was associated with anemia in older people, and the association was stronger in those with lower education, highlighting the significance of early-life psychological stressors assessment and consideration of education background in geriatric care.

Association of fish and meat consumption with non-alcoholic fatty liver disease: Guangzhou Biobank Cohort Study

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Unhealthy dietary habit is one of major risk factors of NAFLD. However, the associations between specific types of fish and meat consumption and NAFLD remain inconclusive. We explored the associations of fish and meat consumption with NAFLD risk in middle-aged and older Chinese.

METHODS

We collected information on 1,862 participants aged 50 years or older from Guangzhou Biobank Cohort Study in 2009 to 2010. Fish and meat consumption was assessed using a validated food-frequency questionnaire. NAFLD was diagnosed by ultrasound. Multivariable logistic regression was used to examine the associations of fish and meat consumption with the presence of NAFLD.

RESULTS

The average age was 61.0 (standard deviation = 6.5) years for the participants, 50.2% were women, and 37.2% were diagnosed with NAFLD. After adjusting for age, sex, education, family income, occupation, smoking status, drinking status, physical activity and several metabolic traits, compared with 0 serving/week (one serving = 50 g), fatty fish consumption of ≥ 3 servings/week showed higher odds of NAFLD (odds ratio (OR) and 95% confidence interval (CI): 1.64 (1.12, 2.39)). The highest (≥ 11 servings/week of red meat and poultry; ≥ 3 servings/week of processed meat) versus the lowest (0-3 servings/week of red meat and poultry; 0 serving/week of processed meat) consumption of all other types of meats, including red meat, poultry and processed meat, showed no association with NAFLD (1.17 (0.75, 1.81), 1.02 (0.42, 2.50) and 0.85 (0.50, 1.45), respectively). Aquatic and sea food, and red meat had negative indirect effects on NAFLD via systolic blood pressure and/or high-density lipoprotein cholesterol. Processed meat had positive indirect effects on NAFLD via body mass index, waist circumference, fasting plasma glucose and triglycerides.

CONCLUSION

High consumption of fatty fish was associated with higher NAFLD risk. Our results, if causal, provide evidence that limiting consumption of fatty fish can be considered as part of NAFLD lifestyle prevention and treatment.

Association of perceived stress with memory decline in older Chinese: The Guangzhou Biobank Cohort Study

BACKGROUND

Previous studies on associations of perceived stress with poor memory performance in older adults showed inconsistent results. We examined the prospective associations of perceived stress with memory decline using data from Guangzhou Biobank Cohort Study (GBCS).

METHODS

Perceived stress was measured by the Perceived Stress Scale (PSS) at baseline (2003-2006), with greater scores indicating greater stress. Memory function was measured by delayed 10-word recall test (DWRT) and immediate 10-word recall test (IWRT), with greater scores indicating better performance, at baseline and follow-up (2008-2012) examinations, analyzed as mean annual change in scores.

RESULTS

9656 participants (72 % women) with mean age 61.6 (standard deviation = 6.4) years were included. During an average of 4.4 years of follow-up, after adjusting for confounders, each one-point greater PSS score was associated with mean annual decline in DWRT scores (β (95 % CI) = -0.005 (-0.008 to -0.002)). Greater Perceived Helplessness (PH) scores, but not Perceived Self-efficacy scores, was associated with greater mean annual decline in DWRT and IWRT scores (β (95 % CI) = -0.005 (-0.009 to -0.001) and - 0.012 (-0.018 to -0.005), respectively), and similar patterns were observed in five out of seven PH items (βs from -0.02 to -0.07). Interaction analysis showed that the association of greater PSS with greater decline in DWRT scores was observed only in those with low family income (β (95 % CI) = -0.08 (-0.13 to -0.04), P for interaction = 0.03).

CONCLUSIONS

Greater perceived stress was associated with a greater decline in delayed recall memory, especially in those with low family income.

Comprehensive information management system for a medical research cohort biobank based on quality by design

BACKGROUND

With the development of big health and big data, cohort research has become a medical research hotspot. As an important repository of human genetic resources, biobanks must adapt to the requirements of large-scale and efficient operation. Thus, biobanks urgently need to design and build a legal, convenient, and efficient information management system.

METHODS

This study applies the concept of "quality by design" to build a comprehensive biobank information management system based on the analysis of user requirements, legal and regulatory risks, and industry-standard requirements. The system integrates the management of scientific research projects, biological specimens, clinical information, quality control, and multi-dimensional information query and development. After 10 months of its operation, the comprehensive management system was evaluated through statistical analysis of the efficiency of the construction of the pregnancy-birth cohort and the quality of genetic resources.

RESULTS

Since the system's launch, the statistics on cohort construction efficiency show that the enrollment rate of eligible pregnant women has increased, and the rate of missing volunteers has dropped. The time needed to establish a 1000-person cohort (with complete biological samples and clinical information in early, middle, and late pregnancy) was reduced, and the effective tracking rate of the samples was 77.42%. The error rate of the deep cryogenic refrigerator decreased, with a clinical information integrity rate of 96.47%.

CONCLUSIONS

The comprehensive biobank information management system constructed with the "quality by design" concept is well suited to meet the requirements of medical research. This study provides a solution for designing a comprehensive information system for medical institutions' biobanks.

AST and ALT APRI Scores and Dysglycemia in Saudi Arabia: A Retrospective Population Study

BACKGROUND

Hyperglycemia is a common symptom of numerous conditions, most notably diabetes mellitus and Cushing's syndrome, and the liver plays a pivotal role in the regulation of glucose metabolism. The AST-platelet ratio index (AST APRI score) and ALT-platelet ratio index (ALT APRI score) are novel parameters whose association with circulating glucose levels remains poorly studied.

METHODS

Laboratory data of 14,177 subjects were retrospectively analyzed for the association between AST and ALT APRI scores and fasting blood glucose (FBG) using the Mann-Whitney U and Kruskal-Wallis tests, Spearman's rank correlation coefficient, prevalence and odds ratio (OR) and ROC curve analysis.

RESULTS

AST and ALT APRI scores showed progressive increases with FBG, and the mean FBG was significantly higher in subjects with high AST (104.9 ± 0.33 to 120.8 ± 3.27, p < 0.0001) and ALT (104.7 ± 0.34 to 111.6 ± 1.30, p < 0.0001) APRI scores. However, the AST APRI score but not the ALT APRI score was affected by age and gender. Notably, both elevated AST and ALT APRI scores were more prevalent in hyperglycemic subjects irrespective of gender and were associated with FBG, albeit through mediator variables. Increased AST (OR = 2.55, 95% CI: 1.46-2.06, p < 0.0001) and ALT (OR = 1.73, 95% CI: 1.46-2.06, p < 0.0001) APRI scores carried a significantly higher risk for hyperglycemia. Importantly, the ALT APRI score was superior to that of the AST APRI score in distinguishing hyperglycemic subjects.

CONCLUSIONS

The AST and ALT APRI scores are inexpensive, novel markers of FBG and may serve as supportive evidence in the diagnosis and management of hyperglycemic conditions.

Low aspartate aminotransferase/alanine aminotransferase (DeRitis) ratio assists in predicting diabetes in Chinese population

Background

Few studies discussed the predictive ability of aspartate aminotransferase/alanine aminotransferase (AST/ALT, DeRitis) ratio for diabetes risk. The aim of this study was to characterize the role of AST/ALT ratio in the prediction of Chinese diabetes.

Methods

This retrospective cohort study analyzed a Chinese population comprising 87,883 participants without diabetes at baseline between 2010 and 2016. Cox proportional hazards regression was used to identify independent risk factors. Restricted cubic spline (RCS) was performed to investigate the non-linear correlation between AST/ALT ratio and diabetes risk.

Results

During a median follow-up period of 3.01 years, 1,877 participants developed diabetes. Comparing the baseline characteristics, diabetes group exhibited lower AST/ALT ratio. The Kaplan-Meier curve showed that participants with low AST/ALT ratio had higher cumulative incidence, and Cox regression also demonstrated that the lower AST/ALT ratio, the higher diabetes risk (HR: 0.56, 95% CI: 0.37-0.85, P = 0.006). The RCS model revealed a non-linear correlation between AST/ALT ratio and diabetes risk. In the condition of AST/ALT ratio ≤1.18, diabetes risk increased as it decreased (HR: 0.42, 95% CI: 0.19-0.91, P = 0.028). In contrast, AST/ALT ratio did not independently affect diabetes when beyond 1.18.

Conclusion

AST/ALT ratio is a valuable predictor of diabetes. Diabetes risk increases rapidly in the condition of AST/ALT ratio ≤1.18.

Association of alcohol use with memory decline in middle-aged and older Chinese: a longitudinal cohort study

BACKGROUND

Previous studies on associations of alcohol use with memory decline showed inconclusive results. We examined these associations using longitudinal data from the Guangzhou Biobank Cohort Study (GBCS) and explored whether these associations varied by sex and age group.

METHODS

Memory function was assessed by delayed 10-word recall test (DWRT) and immediate 10-word recall test (IWRT) at both baseline (2003-2008) and follow-up (2008-2012) examinations, expressed as the mean annual change and mean annual rate of change in scores. Memory cognitive impairment was defined by DWRT scores of less than 4. Multivariable linear regression models and restricted cubic spline were used for data analysis.

RESULTS

Of 14,827 participants without memory cognitive impairment at baseline, 90.2% were never or occasional drinkers, 5% moderate drinkers, 1.5% excessive drinkers, and 3.3% former drinkers. The mean (standard deviation) age was 60.6 (6.6) years old. During an average of 4.1 years follow-up, 1000 (6.7%) participants developed memory cognitive impairment. After adjusting for confounders, compared with never or occasional drinkers, moderate and excessive drinkers had significant decline in DWRT scores (β, 95% confidence interval (CI) = -0.04 (-0.08 to -0.01), and - 0.07 (-0.14 to 0.01), respectively), and IWRT scores (β, 95% CI = -0.10 (-0.19 to -0.01), and - 0.15 (-0.30 to 0.01), respectively) annually. With respect to the mean annual rate of change, moderate and excessive drinkers also showed greater decline in DWRT scores (β, 95% CI = -1.02% (-1.87% to -0.16%), and - 1.64% (-3.14% to -0.14%), respectively). The associations did not vary by sex and age group (all P values for interaction ≥ 0.10).

CONCLUSION

Compared to never or occasional alcohol use, moderate and excessive alcohol users had greater memory decline and the associations did not vary by sex and age group.

Elevated Levels of Serum Alkaline Phosphatase are Associated with Increased Risk of Cardiovascular Disease: A Prospective Cohort Study

AIM

We aimed to investigate the associations of serum alkaline phosphatase (ALP) levels with incident cardiovascular disease (CVD), coronary heart disease (CHD), and stroke, as well as their subtypes, among men and women in a prospective cohort study.

METHODS

A total of 11,408 men and 14,981 women were included to evaluate the associations between ALP levels and incident CVD. Participants were divided into four groups according to the quartiles of serum ALP levels in men and women separately. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During an average follow-up of 7.3 years, 7,015 incident CVDs (5,561 CHDs and 1,454 strokes) were documented. After adjustments for age, body mass index, smoking status, drinking status, diabetes, hyperlipidemia, hypertension, physical activity, aspirin usage, anticoagulants usage, menopausal status (women only), family history of CVD, estimated glomerular filtration rate, white blood cell counts, and admission batch and comparing the lowest quartile of ALP, the adjusted HRs (95% CIs) of participants in the highest quartile were 1.22 (1.11-1.34) for CVD, 1.14 (1.02-1.28) for CHD, 1.43 (1.18-1.73) for stroke, 1.31 (1.09-1.57) for acute coronary syndrome (ACS), 1.37 (1.11-1.70) for ischemic stroke, and 1.75 (1.10-2.79) for hemorrhagic stroke in men and 1.12 (1.01-1.23) for CVD, 1.10 (0.99-1.23) for CHD, 1.18 (0.92-1.51) for stroke, 1.23 (1.03-1.47) for ACS, 1.10 (0.83-1.45) for ischemic stroke, and 1.54 (0.90-2.65) for hemorrhagic stroke in women. The ALP-CVD associations remained significant even within the normal ranges of ALP levels (40-150 U/L). Moreover, linear dose-response relationships were found between ALP levels and incident CVD.

CONCLUSIONS

Higher ALP levels, even within the normal range, were significantly associated with increased risks of CVD, in a dose-dependent manner. These findings suggested that regular monitoring of ALP levels may help in improving the early identification of the population at higher CVD risk.

Impact of chronic hepatitis on cardiovascular events among type 2 diabetes patients in Taiwan pay-for-performance program

To investigate the impact of chronic hepatitis on cardiovascular events in patients with type 2 diabetes mellitus (T2DM). This nationwide retrospective cohort study included 152,709 adult patients (> 20 years) with T2DM enrolled in the National Health Insurance Diabetes Pay-for-Performance Program from 2008 to 2010 and followed up until the end of 2017. Patients were categorized into groups with hepatitis B, hepatitis C, fatty liver disease, and patients without chronic hepatitis. The incidence of cardiovascular events in patients with T2DM and hepatitis C (79.9/1000 person-years) was higher than that in patients with diabetes combined with other chronic hepatitis, or without chronic hepatitis. After adjusting for confounding factors, T2DM with fatty liver (adjusted hazard ratio [HR]: 1.10; 95% confidence interval [CI]: 1.07–1.13) and hepatitis C (adjusted HR: 1.09; 95% CI: 1.03–1.12) demonstrated a significantly higher risk of cardiovascular events. The adjusted visit-to-visit coefficient of variation of HbA1c and fasting blood glucose were associated with a high risk of cardiovascular events (HRs of the highest quartile were 1.05 and 1.12, respectively). Chronic hepatitis affects cardiovascular events in adult patients with T2DM. Glucose variability could be an independent risk factor for cardiovascular events in such patients.

Association Between Serum Aminotransferases and Risk of New-Onset Cardiometabolic Disease in a Healthy Chinese Population: A Cohort Study

Purpose

This study aimed to investigate the association between serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and incident metabolic disease in a cohort of community-based older Chinese people.

Patients and Methods

Five thousand healthy Gaohang residents who attended community health checks at the Shanghai East Hospital in 2013 were recruited. Biological, biochemical, and lifestyle variables were collected. The cohort was followed for new-onset metabolic disease in 2014 and 2017, with a final study population of 3,123 (63%) after follow-up. The study outcome included type-2 diabetes mellitus and metabolic syndrome.

Results

Baseline AST and ALT were associated with incident type-2 diabetes mellitus (HR 1.019, 95% CI 1.006-1.032, p = 0.003 and HR 1.016, 95% CI 1.008-1.025, p < 0.001 respectively). These associations persisted after adjusting for traditional risk factors including age, sex, income, waist circumference, systolic blood pressure, diastolic blood pressure, HbA1c, triglyceride, cholesterol, HDL and eGFR. Baseline AST and ALT were associated with incident metabolic syndrome in the crude analysis (HR 0.980, 95% CI 0.965-0.996, p = 0.012 and HR 0.992, 95% CI 0.988-0.997, p = 0.001, respectively). However, the association between AST and ALT with metabolic syndrome was non-significant after adjusting for biochemical parameters such as the lipid profile.

Conclusion

This study demonstrated that serum AST and ALT are associated with new-onset type-2 diabetes mellitus, independent of traditional risk factors, in a cohort of older Chinese people. These findings may contribute to disease risk stratification and management in type-2 diabetes.

Association of liver enzymes with incident diabetes in US Hispanic/Latino adults

INTRODUCTION

Non-alcoholic fatty liver disease (NAFLD) has been associated with increased risk of incident diabetes. But such evidence is lacking in the Hispanic/Latino population, which has high prevalence of obesity and NAFLD.

METHODS

We conducted a prospective cohort study of 6,928 adults of Hispanic/Latino background who had no diabetes, did not report excessive alcohol use, and no hepatitis B and C infection at baseline (2008-2011). We estimated risk ratios (RR) for incident diabetes, identified from visit 2 examination by glucose measurements or antidiabetic medication use, with baseline liver enzymes (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transpeptidase (GGT)).

RESULTS

A total of 738 adults developed diabetes during 6 years of follow-up. After adjusting for participant characteristics at baseline, versus the lowest quartile, highest quartiles of ALT and GGT were associated with risks for incident diabetes (RR for ALT: 1.51 [95% CI 1.03-2.22], p-trend = 0.006; RR for GGT: 2.39 [1.60-3.55], p-trend = 0.001). Higher GGT levels predicted increased risk of incident diabetes even among those with ALT or AST below the median levels. The associations of ALT and GGT with incident diabetes were similar among most Hispanic background but were not seen among Dominicans (p for interaction <0.05). The association of AST with incident diabetes was found only among light-to-moderate alcohol drinkers (RR = 1.50 [1.20-1.86]) but not abstainers (RR = 0.91 [0.69-1.20], p for interaction = 0.006).

CONCLUSION

Higher ALT and GGT levels are associated with increased risk of developing diabetes among Latinos. Liver enzyme tests might aid in diabetes prevention by identifying high-risk individuals.

Association of fish consumption with risk of all-cause and cardiovascular disease mortality: an 11-year follow-up of the Guangzhou Biobank Cohort Study

BACKGROUND

Whether fish consumption is associated with all-cause, cardiovascular (CVD), ischemic heart disease (IHD) and stroke mortality remains inconclusive. We examined the association of fish consumption with all-cause, cardiovascular (CVD), ischemic heart disease (IHD) and stroke mortality in older men and women in south China.

METHODS

A total of 18,215 participants including men and women without CVD at baseline (2003-2006) from Guangzhou Biobank Cohort Study (GBCS) were included and followed up till December 2017. Deaths were identified through record linkage with the Death Registry. Information on fish consumption was obtained using a food frequency questionnaire.

RESULTS

During an average follow-up of 11.4 (standard deviation = 2.1) years, 2,697 deaths occurred, including 917 total CVD, 397 IHD and 374 stroke deaths. After adjusting for potential confounders, compared with fish consumption of 0-3 servings/week (i.e., 0-21 g/day, one serving = 50 g), consumption of 4-6 servings/week (29-43 g/day) showed significantly lower risks of all-cause and CVD mortality (hazards ratio (HR) and 95% confidence interval (CI): 0.85 (0.76, 0.95) and 0.77 (0.64, 0.93), respectively), but the reduced risk of IHD mortality (HR (95% CI): 0.80 (0.60, 1.07)) was not significant. Consumption of 7-10 servings/week or higher showed no association with all-cause, CVD, IHD, and stroke mortality.

CONCLUSIONS

Moderate fish consumption of 4-6 servings/week (29-43 g/day) was associated with lower all-cause and CVD mortality risk. Our findings support the current general advice on regular fish consumption also in middle-aged and older adults.

Mortality in relation to changes in physical activity in middle-aged to older Chinese: An 8-year follow-up of the Guangzhou Biobank Cohort Study

BACKGROUND

Physical activity (PA) is generally encouraged. Studies from developed countries in the West have shown that maintenance of adequate PA or increasing PA are associated with lower mortality risk. It is unclear whether these associations apply to an older Chinese population. Hence, we examined the changes in PA prospectively among a middle-aged and older Chinese population over an average of 4 years and explored their subsequent mortality risks.

METHODS

Metabolic equivalent scores of PA among participants in the Guangzhou Biobank Cohort Study were calculated. Participants were divided into 3 groups related to PA level, and changes in PA were classified into 9 categories. Information on vital status and causes of death from March 2008 to December 2012 (the first repeated examination) until December 31, 2017, was obtained via record linkage with the Death Registry.

RESULTS

Of 18,104 participants aged 61.21 ± 6.85 years (mean ± SD), 1461 deaths occurred within 141,417 person-years. Compared to participants who maintained moderate PA, those who decreased PA from moderate or high levels to a low level had increased risks for all-cause mortality (hazard ratio (HR) = 1.47, 95% confidence interval (95%CI): 1.11-1.96). Participants who maintained a high level of PA (HR = 0.83, 95%CI: 0.70-0.98) or increased PA from low to high levels (HR = 0.71, 95%CI: 0.52-0.97) showed lower all-cause mortality risks. Those who maintained low PA levels showed a higher all-cause mortality risk, whereas those who increased their PA levels showed a non-significantly lower risk. Similar results were found for cardiovascular disease risk.

CONCLUSION

Even at an older age, maintaining a high PA level or increasing PA from low to high levels results in lower mortality risks, suggesting that substantial health benefits might be achieved by maintaining or increasing engagement in adequate levels of PA. The increased risk of maintaining a low PA level or decreasing PA to a low level warrants the attention of public health officials and clinicians.

Effects of hepatitis B virus infection, alanine aminotransferase, aspartate aminotransferase and gamma-glutamyl transferase on prediabetes and diabetes mellitus: A cohort study

INTRODUCTION AND OBJECTIVES

The purpose of this study was to confirm whether hepatitis B virus (HBV) infection and the levels of liver enzymes would increase the risk of prediabetes and diabetes mellitus (DM) in China.

MATERIALS AND METHODS

A total of 10,741 individuals was enrolled in this prospective cohort study. Cox regression analysis was used to calculate the Hazard ratios (HRs) to evaluate the relationships between HBV infection and the risk of DM and prediabetes. Decision trees and dose response analysis were used to explore the effects of liver enzymes levels on DM and prediabetes.

RESULTS

In baseline population, HBV infection ratio was 5.31%. In non-adjustment model, the HR of DM in HBV infection group was 1.312 (95% CI, 0.529-3.254). In model adjusted for gender, age and liver cirrhosis, the HR of DM in HBV infection group were 1.188 (95% CI, 0.478-2.951). In model adjusted for gender, age, liver cirrhosis, smoking, drinking, the HR of DM was 1.178 (95% CI, 0.473-2.934). In model further adjusted for education, family income and occupation, the HR of DM was 1.230 (95% CI, 0.493-3.067). With the increases of levels of Alanine aminotransferase (ALT), Aspartate aminotransferase (AST) and Gamma-glutamyl transferase (GGT), the risk of prediabetes was gradually increasing (P_{non-linearity}<0.05). There were dose-response relationships between ALT, GGT and the risk of DM (P_{non-linearity}<0.05).

CONCLUSIONS

HBV infection was not associated with the risk of prediabetes and DM. The levels of liver enzymes increased the risk of prediabetes and DM.

Considering serum alanine aminotransferase and gamma-glutamyltransferase levels together strengthen the prediction of impaired fasting glucose risk: a cross-sectional and longitudinal study

Emerging data suggest that an increase in serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) as biomarkers of oxidative stress are associated with increased risk of impaired fasting glucose (IFG). The present study was an investigation of whether an increase in serum ALT and GGT had a combined effect on increasing IFG risk through cross-sectional and longitudinal studies. In the cross-sectional study, data were analyzed from 9937 subjects without diabetes who underwent health check-ups between 1999 and 2001 (baseline data). In the longitudinal study, 6390 subjects were analyzed who had been rechecked between 2009 and 2014, excluding IFG patients from baseline data. In cross-sectional analysis, adjusted odds ratio (OR) of IFG in the fourth quartile of both ALT and GGT was 1.829 (95% confidence interval [CI] 1.545–2.164) compared with the reference group (1st and 2nd quartiles of ALT and GGT). In longitudinal analysis, IFG probability increased gradually with an increase in the circulating levels of ALT and GGT. Adjusted hazard ratios for developing IFG in the fourth quartile of both ALT and GGT was 1.625 (95% CI 1.263–2.091) compared with the reference group (1st and 2nd quartiles). Increased serum ALT and GGT levels are well associated with IFG after potential confounders are adjusted for, and elevated ALT and GGT at the same time can have a combined effect in predicting the development of IFG.

Adiposity change and mortality in middle-aged to older Chinese: an 8-year follow-up of the Guangzhou Biobank Cohort Study

OBJECTIVE

To examine the associations of change in body mass index (BMI) and waist circumference (WC) over an average of 4 years with subsequent mortality risk in middle-aged to older Chinese.

DESIGN

Prospective cohort study based on the Guangzhou Biobank Cohort Study.

SETTING

Community-based sample.

PARTICIPANTS

17 773 participants (12 956 women and 4817 men) aged 50+ years.

PRIMARY AND SECONDARY OUTCOME MEASURES

Primary outcome measure was all-cause mortality. Secondary outcome measures were cardiovascular disease (CVD) and cancer mortality. Causes of death were obtained via record linkage, and coded according to the International Classification of Diseases (tenth revision).

RESULTS

1424 deaths (53.4% women) occurred in the 17 773 participants (mean age 61.2, SD 6.8 years) during an average follow-up of 7.8 (SD=1.5) years, and 97.7% of participants did not have an intention of weight loss . Compared with participants with stable BMI, participants with BMI loss (>5%), but not gain, had a higher risk of all-cause mortality (HR=1.49, 95% CI 1.31 to 1.71), which was greatest in those who were underweight (HR=2.45, 95% CI 1.31 to 4.59). Similar patterns were found for WC. In contrast, for participants with a BMI of ≥27.5 kg/m², BMI gain, versus stable BMI, was associated with 89% higher risk of all-cause mortality (HR=1.89, 95% CI 1.25 to 2.88), 72% higher risk of CVD mortality (HR=1.72, 95% CI 0.80 to 3.72) and 2.27-fold risk of cancer mortality (HR=2.27, 95% CI 1.26 to 4.10).

CONCLUSION

In older people, unintentional BMI/WC loss, especially in those who were underweight was associated with higher mortality risk. However, BMI gain in those with obesity showed excess risks of all-cause and cancer mortality, but not CVD mortality. Frequent monitoring of changes in body size can be used as an early warning for timely clinical investigations and interventions and is important to inform appropriate health management in older Chinese.

Association of hepatitis B surface antigen seropositivity and hepatitis B surface antibody seropositivity with diabetes: a cross-sectional study based on two Chinese populations in Guangdong, China

OBJECTIVES

To examine whether hepatitis B surface antigen (HBsAg) seropositivity and hepatitis B surface antibody (HBsAb) seropositivity were associated with the presence of diabetes in two population-based studies in southern China, the Guangzhou Biobank Cohort Study (GBCS) and the Major Infectious Disease Prevention and Control (MIDPC) study.

DESIGN

A cross-sectional study.

SETTING

The GBCS was conducted among a community social and welfare organisation with branches in all 10 districts of Guangzhou. The MIDPC was conducted among the community residents in two districts of Guangzhou and three districts of Zhongshan.

PARTICIPANTS

4947 participants from the GBCS and 4357 participants from the MIDPC were included in this study.

PRIMARY AND SECONDARY OUTCOME MEASURES

Type 2 diabetes was the main study outcome, which was diagnosed by fasting blood glucose ≥7.0 mmol/L, and/or self-reported history of diabetes.

RESULTS

After adjusting for age, sex, education, occupation, smoking status, alcohol use, physical activity and body mass index, we found no association of HBsAg seropositivity in GBCS or MIDPC (OR=1.12, 95% CI 0.74 to 1.69, and OR=0.83, 95% CI 0.59 to 1.17, respectively), and HBsAb seropositivity (OR=0.85, 95% CI 0.65 to 1.12, OR=1.00, 95% CI 0.86 to 1.16, respectively) with the presence of diabetes. Null associations were found for analysis pooling GBCS and MIDPC data after similar adjustment. The adjusted OR for the associations of HBsAg seropositivity and HBsAb seropositivity with the presence of diabetes in the pooled sample was 0.91 (95% CI 0.70 to 1.19) and 0.98 (95% CI 0.86 to 1.12), respectively.

CONCLUSIONS

Taking advantage of data from two large cross-sectional studies, we found no association of serological status of HBsAg and HBsAb with the presence of diabetes or glucose measures.

Serum Alanine Transaminase as a Predictor of Type 2 Diabetes Incidence: The Yuport Prospective Cohort Study

Prior studies have shown an association between the incidence of diabetes with liver enzymes, such as alanine transaminase (ALT). Liver fibrosis scores, such as the Fibrosis-4 index which indicates chronic liver damage, were also associated with diabetes development. However, no literature compared predictive accuracy between ALT and Fibrosis-4 index. Thus, we aimed to determine it, and to assess its association using inverse probability of treatment weighting. This was a non-concurrent prospective cohort study of 9,748 subjects without diabetes receiving Yuport Health Checkup in Japan between 1998 and 2006. ALT was categorized into three groups: the highest ALT group (men ≥ 30 U/L and women ≥ 20 U/L), the middle (men ≥ 20 and < 30 U/L, and women ≥ 14 and < 20 U/L), and the lowest (men < 20 U/L and women < 14 U/L). The primary outcome was the new onset of diabetes. The area under the receiver operating characteristic curves (AUC) of ALT for predicting the diabetes development was higher than that of any other markers of liver damage. The AUC for ALT was 0.71, while that for the Fibrosis-4 index was 0.51 (p < 0.001 for the difference between the AUCs). The highest and middle ALT groups had a significantly higher incidence of diabetes than the lowest group: adjusted relative risk 1.79 [95% confidence interval (CI): 1.29, 2.58], and 1.64 [95% CI: 1.17, 2.38] respectively. Of the various indicators of liver function, ALT is likely to be the most accurate and associated predictor of diabetes development.

Serum alanine transaminase levels predict type 2 diabetes risk among a middle-aged and elderly Chinese population

INTRODUCTION AND AIM

It is indicated that high levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are associated with increased incident type 2 diabetes risk. However, whether serum ALT levels could improve the discrimination of type 2 diabetes remains unclear.

METHODS

The data was derived from the Dongfeng-Tongji cohort study, which was established in 2008 and followed until October 2013. A total of 17,173 participants free of type 2 diabetes at baseline were included and 1159 participants developed diabetes after 4.51 (0.61) years of follow-up. Cox proportional hazard regression model was used to calculate the hazard ratios (HRs) for the association between ALT and AST levels with incident diabetes risk. Receiver-operating characteristic (ROC) curves analysis was used to evaluate the predictive accuracy of models incorporating traditional risk factors with and without ALT.

RESULTS

Compared with the lowest quartile of ALT and AST levels, the highest quartile had a significantly higher risk of developing type 2 diabetes (HR: 2.17 [95% CI: 1.78-2.65] and 1.29 [1.08-1.54], respectively) after adjustment for potential confounders. The addition of ALT levels into the traditional risk factors did not improve the predictive ability of type 2 diabetes, with AUC increase from 0.772 to 0.774; P=0.86.

CONCLUSIONS

Although elevated ALT or AST levels increased incident type 2diabetes risk, addition of ALT levels into the prediction model did not improve the discrimination of type 2 diabetes.

Prevalence of elevated liver enzymes and its association with type 2 diabetes: A cross-sectional study in Bangladeshi adults

BACKGROUND

Type 2 diabetes (T2D) is a major public health concern affecting millions of people worldwide. The relationship between liver enzymes and T2D has been reported in limited studies; however, there is still a lack of evidence for the Bangladeshi population. This study aimed to evaluate the prevalence of elevated liver enzymes and examine its association with the prevalence of T2D in Bangladeshi adults.

METHODS

A total of 270 individuals (110 diabetic and 160 nondiabetic) were enrolled in the study. Alanine and aspartate aminotransferase (ALT, AST), alkaline phosphatase (ALP) and γ-glutamyltransferase (GGT) activities were measured in blood serum collected from them. T2D was defined as fasting blood glucose (FBG) ≥126 mg/dL or self-reported recent use of insulin or antidiabetic medications. Association between liver enzymes and T2D was evaluated by multinomial logistic regression analysis.

RESULTS

Overall, 61.2% of participants in T2D and 37.1% of participants in the nondiabetes group had at least one or more elevated liver enzymes. The mean concentrations of serum ALT, AST, ALP and GGT were significantly higher in the T2D group compared to the nondiabetes group. The prevalence of elevated liver enzymes was significantly higher in the diabetes group compared to the nondiabetes group (P < .01). In regression analysis, serum GGT activity showed an independent association with the prevalence of T2D.

CONCLUSIONS

A high prevalence of elevated liver enzymes was observed in subjects having diabetes. Increased serum GGT activity was independently associated with the prevalence of T2D among Bangladeshi adults. More studies of this nature should be carried out in developing countries to get proper insights into the involvement of liver enzymes in T2D.

Glycemic Measures and Risk of Mortality in Older Chinese: The Guangzhou Biobank Cohort Study

CONTEXT

China has the largest number of people with type 2 diabetes mellitus (T2DM) in the world. Data from previous studies have suggested that up to one-fifth of individuals with diabetes would be missed without an oral glucose tolerance test (OGTT). To date, there is little information on the mortality risk of these individuals.

OBJECTIVE

We estimated the association of different indicators of hyperglycemia with mortality in the general Chinese population.

DESIGN

Prospective cohort study.

SETTING

China.

PARTICIPANTS

A total of 17 939 participants aged 50+ years.

EXPOSURES

Previously diagnosed diabetes and newly detected diabetes defined by fasting glucose (≥7.0 mmol/L), 2-hour postload glucose (≥11.1 mmol/L), or hemoglobin A1c (HbA1c, ≥6.5%).

MAIN OUTCOMES MEASURES

Deaths from all-cause, cardiovascular disease, and cancer were identified by record linkage with death registration.

RESULTS

During 7.8 (SD, 1.5) years' follow-up, 1439 deaths were recorded. Of 3706 participants with T2DM, 2126 (57%) had known T2DM, 118 (3%) were identified by isolated elevated fasting glucose, 1022 (28%) had isolated elevated postload glucose, and 440 (12%) had both elevated fasting and postload glucose. Compared with normoglycemia, the hazard ratio (95% confidence interval) of all-cause mortality was 1.71 (1.46-2.00), 0.96 (0.47-1.93), 1.43 (1.15-1.78), and 1.82 (1.35-2.45) for the 4 groups, respectively. T2DM defined by elevated HbA1c was not significantly associated with all-cause mortality (hazard ratio, 1.17; 95% confidence interval, 0.81-1.69).

CONCLUSION

Individuals with isolated higher 2-h postload glucose had a higher risk of mortality by 43% than those with normoglycemia. Underuse of OGTT leads to substantial underdetection of individuals with a higher mortality risk and lost opportunities for early intervention.

The effect of liver enzymes on adiposity: a Mendelian randomization study

Poorer liver function is positively associated with diabetes in Mendelian randomization (MR) studies. Observationally, adiposity is associated with poorer liver function. To clarify the etiology, we assessed the association of liver enzymes with adiposity observationally and using two-sample MR for validation. In the "Children of 1997" birth cohort, we used multivariable linear regression to assess the associations of alanine transaminase (ALT) and alkaline phosphatase (ALP) at ~17.5 years with body mass index (BMI) (n = 3,458). Using MR, genetic predictors of ALT, ALP and gamma glutamyltransferase (GGT), were applied to genome-wide association studies of BMI (n = 681,275), waist circumference (WC) (n = 224,459) and waist-hip ratio (WHR) (n = 224,459) to obtain unconfounded estimates. Observationally, ALT was positively associated with BMI (0.10 kg/m² per IU/L, 95% confidence interval (CI) 0.09 to 0.11). ALP was inversely associated with BMI (-0.018 kg/m² per IU/L, 95% CI -0.024 to -0.012). Using MR, ALT was inversely associated with BMI (-0.14 standard deviation per 100% change in concentration, 95% CI -0.20 to -0.07), but not WC or WHR. ALP and GGT were unrelated to adiposity. Poorer liver function might not cause adiposity; instead higher ALT might reduce BMI, raising the question as to the role of ALT in body composition.

Association of liver enzymes levels with fasting plasma glucose levels in Southern China: a cross-sectional study

OBJECTIVE

According to several studies, liver enzymes levels are associated with fasting plasma glucose (FPG) levels. However, the association stratified by body mass index (BMI) remains to be elucidated, especially in Southern China. Therefore, the aim of this study was to investigate the correlation between liver enzymes levels and FPG levels stratified by BMI in Southern China.

DESIGN

Cross-sectional study.

PARTICIPANTS AND SETTING

3056 individuals participated in real-time interviews and blood tests in Southern China. Participants were divided into three groups (underweight, normal weight and overweight or obesity) based on BMI cut-offs.

MAIN OUTCOME MEASURED

Partial correlation analysis was performed to investigate the relationship between FPG levels and liver tests. Multivariate logistic regression analyses were applied to calculate the adjusted ORs for FPG levels based on liver enzymes levels.

RESULTS

There was no association between liver enzymes and FPG either in the underweight group or in the normal weight group; however, a significant correlation was observed in the overweight or obesity group (alanine transaminase (ALT), p<0.01; aspartate aminotransferase (AST), p<0.05). After adjusting for confounding factors, the highest tertiles of ALT still remained significantly positively related to FPG levels in the overweight or obesity group, with an OR of 2.205 (95% CI 1.442 to 3.371) for the 5.56≤FPG<7.00 mmol/L vs the FPG<5.56 mmol/L group and with an OR of 2.297 (95% CI 1.017 to 5.187) for the FPG≥7.00 mmol/L vs the FPG<5.56 mmol/L group, but this correlation was not found for AST.

CONCLUSIONS

The association of liver enzymes levels with FPG levels differed based on different BMI cut-offs. ALT levels were significantly positively associated with FPG levels in the overweight or obesity group, but not in the other two groups; AST levels were not associated with FPG levels in any group.

Independent effect of alanine transaminase on the incidence of type 2 diabetes mellitus, stratified by age and gender: A secondary analysis based on a large cohort study in China

BACKGROUND

Previous studies have revealed that alanine aminotransferase (ALT) may be one of the risk factors of developing diabetes. We aimed to demonstrate the independent effect of ALT on incident diabetes and to investigate whether the association between ALT and incident diabetes is modified by age and gender in the general Chinese population.

METHODS

The present study was a retrospective cohort study, including 210,051 Chinese adult participants. The primary outcome was developing diabetes. The serum ALT activities were stratified by quintiles. We obtained data from 'DATADRYAD' website and used the data for secondary analysis.

RESULTS

At a median follow-up of 3.0 y, 4144 of 210,051 (1.97%) participants developed diabetes. After adjustment for potential confounders, a significantly higher risk of the incident diabetes (HR: 1.43, 95% CI: 1.25-1.63) was found in participants in the fifth quintile (Q5, ≥31 U/L) compared to those in the first to fourth quintiles (Q1-4) for ALT activities. Among males aged 30 to 40 and 40 to 50 y with the fifth quintile of ALT activity had 2.4- and 1.5-fold increased odds of developing diabetes, respectively, in comparison with those in the lower ALT activities. Among females with age 30 to 40 and ≥ 70 y, the fifth quintile of ALT activity had 4.9- and 2.2-fold increased odds for incident diabetes.

CONCLUSION

Our result indicated that the ALT activity was positively associated with the incident diabetes among Chinese persons. Moreover, 30-40 y individuals, whether male or female, with elevated ALT activities had the greatest increased risk for diabetes compared with persons with lower ALT activities in the same age group.

Associations of Insulin Resistance and Glycemia With Liver Enzymes in Hispanic/Latino Youths: Results From the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

BACKGROUND

Associations of insulin resistance and hyperglycemia with a panel of liver enzymes have not been well studied in a young, heterogenous Hispanic/Latino population. We aimed to assess the associations of insulin resistance and glycemia with nonalcoholic fatty liver disease (NAFLD), as measured by liver enzymes and the pediatric NAFLD fibrosis index (PNFI), and whether these associations are modified by body mass index and mediated by inflammation or endothelial dysfunction.

MATERIALS AND METHODS

We conducted a cross-sectional study of 1317 boys and girls aged 8 to 16 years from the Hispanic Community Children's Health Study/Study of Latino Youth. We used Poisson regression to assess the associations of fasting glucose, hemoglobin A1c, and homeostasis model assessment of insulin resistance (HOMA-IR) with elevated alanine aminotransferase (ALT) (>25 U/L in boys, >22 U/L in girls), aspartate aminotransferase (AST) (≥37 U/L), gamma-glutamyl transpeptidase (GGT) (≥17 U/L), and PNFI (≥9; a function of age, waist circumference, and triglyceride level).

RESULTS

HOMA-IR was associated with elevated ALT, AST, GGT, and PNFI [prevalence ratios (95% confidence intervals) for each 1-unit increase in the natural log of HOMA-IR: 1.99 (1.40-2.81), 2.15 (1.12-4.12), 1.70 (1.26-2.30), and 1.98 (1.43-2.74), respectively]. Associations were observed in overweight/obese children, but not in normal weight children (P-interaction=0.04 for AST and P-interaction=0.07 for GGT). After further adjustment for adiponectin, high-sensitivity C-reactive protein, e-selectin, and PAI-1, associations of HOMA-IR with liver enzymes and PNFI were attenuated, but remained statistically significant for AST and PNFI.

CONCLUSION

Insulin resistance was associated with NAFLD in overweight/obese Hispanic/Latino youth, and this association may be partially mediated by inflammation and endothelial dysfunction.

High relative risk of all-cause mortality attributed to smoking in China: Guangzhou Biobank Cohort Study

BACKGROUND

Prediction of disease burden in China arising from smoking based on earlier cohorts in the West and China could not reflect the disease burden at the current stage accurately. No cohort studies in China focused specifically on people born since 1950. We examined the risk of all-cause mortality attributed to smoking in adults in Guangzhou, the city with the most rapidly expanding economy in China.

METHODS AND FINDINGS

This population-based prospective cohort included 21,658 women and 8,284 men aged 50+ years enrolled from 2003-2008 and followed until January 2016. During an average follow-up of 8.8 (standard deviation = 1.8) years, 2,986 (1,586 women, 1,400 men) deaths were recorded. After adjustment for confounders, the hazards ratios (95% confidence interval (CI)) of all-cause mortality in current versus never smokers increased from 1.61 (95% CI 1.45-1.80) in those born in 1920-1939 to 2.02 (95% CI 1.74-2.34), and 4.40 (95% CI 3.14-6.17), in those born in the 1940s and 1950s, respectively (P for trend 0.009).

CONCLUSIONS

In smokers born after 1949 in Guangzhou and other areas which have the longest history of smoking, the mortality risk could have reached three fold that of non-smokers, as in the UK, US and Australia. If confirmed, unless China quickly and strictly complies with the WHO Framework Convention on Tobacco Control with massive smoking cessation in the population, this is a more striking warning that China will be facing an even larger disease burden from tobacco use than previous forecasts.

Sex-Specific Association between Metabolic Abnormalities and Elevated Alanine Aminotransferase Levels in a Military Cohort: The CHIEF Study

The association of metabolic syndrome (MetS) components with elevated serum alanine aminotransferase (ALT) levels, a marker of hepatic injury, may differ between men and women. However, the sex-specific association in a military young population which has a low prevalence of MetS was unclear. We conducted a cross-sectional examination in 6738 men and 766 women, aged 18-50 years, from the cardiorespiratory fitness study in armed forces (CHIEF) in eastern Taiwan. The components of MetS were defined according to the updated International Diabetes Federation (IDF) ethnic criteria for Asians. Elevated ALT levels were defined as ≥40 U/L for both sexes and ≥30 U/L for women alternatively. Multivariate logistic regression analysis was performed to determine the sex-specific association between MetS components and elevated ALT. The prevalence of MetS and elevated ALT in men were 11.9% and 12.7% respectively, and in women were 3.5%, and 3.8% respectively. In men, high-density lipoprotein < 40 mg/dL, blood pressures ≥ 130/85 mmHg, serum triglycerides ≥ 150 mg/dL, and waist size ≥ 90 cm were associated with elevated ALT (odds ratios (OR) and 95% confidence intervals: 1.59 (1.34-1.90), 1.40 (1.19-1.65), 2.00 (1.68-2.39), and 1.68 (1.38-2.04); all p < 0.001); whereas in women, only fasting plasma glucose ≥ 100 mg/dL was associated with elevated ALT ≥ 40 U/L (OR: 7.59 (2.35-24.51), p = 0.001) and ALT ≥ 30 U/L (2.67 (0.89-7.95), p = 0.08). Our findings suggest that the relationship between metabolic abnormalities and elevated ALT may differ by sex, possibly due to the MetS more prevalent in young adult men than in women.

Liver Enzymes, Fatty Liver and Type 2 Diabetes Mellitus in a Jinchang Cohort: A Prospective Study in Adults

OBJECTIVES

It is unclear whether liver enzymes or the interactions of various liver enzymes is a predictor of type 2 diabetes mellitus (T2DM), which is independent of fatty liver.

METHODS

A total of 48,001 subjects participated in baseline examinations. Among the subjects, 33,355 were followed for an average of 2.2 years. Cox proportional hazard models were used to examine the adjusted associations of AST, GGT and ALT with T2DM.

RESULTS

The cumulative incidence of T2DM was 8.05% to 9.02% for fatty liver and 2.25% to 4.10% for non-fatty liver, both showing statistically significant differences. Compared with the normal liver enzyme levels in the group with fatty liver, the adjusted incident hazard ratios in T2DM were: ALT 1.23 (95% CI 1.10 to 1.50); AST 1.30 (95% CI 1.07-1.59); and GGT 1.34 (95% CI 1.08 to 1.65). In addition, compared with the normal liver enzyme levels in the group with non-fatty liver, the adjusted incident hazard ratios in type 2 diabetes were: ALT 1.27 (95% CI 1.02 to 1.59); AST 1.33 (95% CI 1.02 to 1.59); and GGT 1.53 (95% CI 1.19 to 1.98). There are significant interactions of T2DM hazard ratios between GGT and ALT and between GGT and AST in addition to ALT and AST.

CONCLUSIONS

Our results suggest that the incidence of T2DM in the group with fatty liver is significantly higher than that in the normal population, and the rise of serum AST, GGT and ALT levels are risk factors independent of fatty liver for the development of T2DM after adjusting for confounding factors.

Mendelian randomization estimates of alanine aminotransferase with cardiovascular disease: Guangzhou Biobank Cohort study

Observational studies of the association of alanine aminotransferase (ALT) levels with ischaemic heart disease (IHD) and cardiovascular disease (CVD) risk factors are inconsistent, probably because of confounding and reverse causality. Mendelian randomization (MR) provides less confounded results. We used MR analysis to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors. We used instrumental variable analysis based on two single nucleotide polymorphism (SNPs) HSD17B13/MAPK10 (rs6834314) and PNPLA3/SAMM50 (rs738409) to assess the associations of ALT (U/L) with IHD, diabetes and other CVD risk factors in the Guangzhou Biobank Cohort Study (GBCS). Observationally in 19,925 participants ALT levels were strongly positively associated with self-reported IHD, systolic and diastolic blood pressure, low-density lipoprotein- and total cholesterol, triglycerides, fasting glucose, body mass index, waist circumference, heart rate (HR) and diabetes, but were not associated with uncorrected QT interval, HR-corrected QT interval or high-density lipoprotein-cholesterol. In the MR study, using a credible genetic instrument (F-statistic = 23) for ALT, ALT levels were negatively associated with IHD (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.87 to 0.97) and triglycerides (β - 0.08, 95% CI - 0.13 to - 0.03), but were not associated with other CVD risk factors. Our results using Mendelian randomization suggest that ALT reduces the risk of IHD, probably through reducing triglyceride levels. The underlying mechanisms deserve further investigation.

Liver Enzymes and Risk of Ischemic Heart Disease and Type 2 Diabetes Mellitus: A Mendelian Randomization Study

We used Mendelian randomization to estimate the causal effects of the liver enzymes, alanine aminotransferase (ALT), alkaline phosphatase (ALP) and gamma glutamyltransferase (GGT), on diabetes and cardiovascular disease, using genetic variants predicting these liver enzymes at genome wide significance applied to extensively genotyped case-control studies of diabetes (DIAGRAM) and coronary artery disease (CAD)/myocardial infarction (MI) (CARDIoGRAMplusC4D 1000 Genomes). Genetically higher ALT was associated with higher risk of diabetes, odds ratio (OR) 2.99 per 100% change in concentration (95% confidence interval (CI) 1.62 to 5.52) but ALP OR 0.92 (95% CI 0.71 to 1.19) and GGT OR 0.88 (95% CI 0.75 to 1.04) were not. Genetically predicted ALT, ALP and GGT were not clearly associated with CAD/MI (ALT OR 0.74, 95% CI 0.54 to 1.01, ALP OR 0.86, 95% CI 0.64 to 1.16 and GGT OR 1.08, 95% CI 0.97 to 1.19). We confirm observations of ALT increasing the risk of diabetes, but cannot exclude the possibility that higher ALT may protect against CAD/MI. We also cannot exclude the possibility that GGT increases the risk of CAD/MI and reduces the risk of diabetes. Informative explanations for these potentially contradictory associations should be sought.