Low alanine aminotransferase levels and higher number of cardiovascular events in people with Type 2 diabetes: analysis of the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study

Associations of serum aminotransferase and the risk of all-cause and cause-specific mortality in Chinese type 2 diabetes: a community-based cohort study

OBJECTIVE

Investigating the associations of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) with all-cause, cardiovascular disease (CVD) and cancer mortality in a large cohort of community-dwelling patients with type 2 diabetes mellitus (T2DM).

DESIGN

Community-based prospective cohort study conducted between 2013 and 2014.

SETTING

44 selected townships in Changshu and Huai'an City, Jiangsu province, China.

PARTICIPANTS

20340 participants with T2DM were recruited in Jiangsu province, China.

METHODS

We use Cox proportional hazard models to estimate the HR and 95% CIs of associations of serum ALT and AST levels with all-cause and cause-specific mortality. Restricted cubic splines were used to explore the dose-response relationships between ALT and AST levels with mortality.

RESULTS

ALT and AST levels were inversely associated with CVD mortality, compared with the lowest quintile (Q1), the multivariable HRs of the highest quintile (Q5) was 0.82 (95% CI: 0.66 to 1.01, p for trend=0.022) and 0.78 (95% CI: 0.63 to 0.96, p for trend=0.022), respectively. Furthermore, the HRs for ALT levels in all-cause mortality were 0.90 (95% CI: 0.79 to 1.01, p for trend=0.018), and the HRs for AST levels in cancer mortality were 1.29 (95% CI: 1.02 to 1.63, p for trend=0.023). Stronger inverse effects of ALT and AST levels on all-cause mortality were observed in the older subgroup and in those with dyslipidaemia (all p for interaction <0.05). Further analysis based on gender showed that the associations between serum aminotransferases and the mortality risk were more significant in women and substantially attenuated in men.

CONCLUSION

Our findings suggested patients with T2DM with lower levels of ALT and AST had an increased risk of CVD mortality, which needs confirmation in future clinical trials.

Effect of a mixture of pyrethroids at doses similar to human exposure through food in the Indian context

Residual amounts of pyrethroids were detected in rice and vegetables of the Indian market. Thus, consumers are exposed to a mixture of pyrethroids on a daily basis through food. Though a large number of studies reported the toxic effects of pyrethroids, there are no reports that used doses equivalent to human consumption. In this study, male Wistar rats were exposed daily to a mixture of pyrethroids for 1-15 months which is equivalent to the amount present in rice and vegetables consumed by an average Indian each day. The oxidant-antioxidant status (lipid peroxidation, nitric oxide; activities of catalase, glutathione peroxidase, glutathione S transferase, and superoxide dismutase) and anatomical changes in the general organs (liver, lung, and kidney) and male reproductive tract tissues (caput, cauda, testis, and prostate) were evaluated. Further, liver and kidney function tests, lipid profile, and complete blood picture were analyzed. Increased oxidative stress, perturbations in the antioxidant enzyme activities, and damage to the anatomical architecture were observed. Disturbances in the liver function and lipid profile were significant. Results of our study demonstrate that exposure to a mixture of pyrethroids at a dose that is equivalent to human consumption can cause systemic and reproductive toxicity, which may ultimately result in the development of lifestyle diseases. This first line of evidence will fuel further studies to determine the impact of food-based pyrethroid exposure on the long-term health of humans and to envisage policies to reduce pesticide content in food products.

Paraoxonase-2 variants potentially influence insulin resistance, beta-cell function, and their interrelationships with alanine aminotransferase in type 2 diabetes

Background:

The aim of this study was to determine whether insulin resistance, beta-cell function, and their associations with alanine aminotransferase (ALT) are affected by the functional variants of paraoxonase-2 (PON2) as an intracellular antioxidant in patients with type 2 diabetes (T2D).

Materials and Methods:

Quantitative insulin sensitivity check index (QUICKI) and homeostasis model assessment for beta-cell function (HOMA-BCF) were assessed in T2D patients. Insulin levels were determined using ELISA. The variants PON2-A148G and PON2-S311C were genotyped using polymerase chain reaction-based restriction fragment length polymorphism.

Results:

According to the PON2-G148A variant, ALT was found to be significantly correlated with QUICKI (r = −0.616, P = 0.005) and HOMA-BCF (r = 0.573, P = 0.01) in the GA + GG group; however, the correlations were not statistically significant in the AA genotypes. Based on the genotypes of PON2-S311C, there was a significant correlation between ALT with QUICKI (r = −0.540, P = 0.031) and HOMA-BCF (r = 0.567, P = 0.022) in the SC + CC group. In the multiple adjusted logistic regression analyses, considering the variants PON2-G148A and PON2-C311S as independent variables and QUICKI and HOMA-BCF as the dependent variables, both variants were significantly associated with the QUICKI (P = 0.019 for PON2-G148A and P = 0.041 for PON2-C311S). Furthermore, PON2-C311S remained significantly associated with HOMA-BCF (P = 0.03).

Conclusion:

These data implicate a role for the functional variants of PON2 in insulin resistance and beta-cell function as well as underscore the effective role of these variants in the associations between them and ALT. Our data contribute to our understanding of the important physiologic functions of PON2 in glucose metabolism and its related metabolic diseases.

Baseline Circulating FGF21 Concentrations and Increase after Fenofibrate Treatment Predict More Rapid Glycemic Progression in Type 2 Diabetes: Results from the FIELD Study

BACKGROUND

It is not known whether circulating fibroblast growth factor 21 (FGF21) concentrations are associated with glycemic progression in patients with established type 2 diabetes. This study reports this relationship in type 2 diabetes patients participating in the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) trial.

METHODS

Plasma FGF21 was quantified in 9697 study participants. Among patients with lifestyle-only glucose control measures at baseline, glycemic progression was defined as the initiation of oral hypoglycemic agents or insulin therapy. We assessed the relationship of FGF21 concentrations with glycohemoglobin (Hb A1c), the homeostasis model assessment of β-cell function (HOMA-B) and insulin resistance (HOMA-IR), and glycemic progression.

RESULTS

Among 2584 patients with lifestyle-only glycemic therapy at baseline, plasma FGF21 concentrations were positively associated with HOMA-IR (5.1% increase per 100% increase in FGF21 concentrations). Patients with higher baseline plasma FGF21 concentrations had higher risk of glycemic progression over a 5-year period (P = 0.02), but the association was not significant after further adjusting for alanine aminotransferase (ALT) enzyme activity. During the fenofibrate active run-in phase, higher tertiles of fenofibrate-induced increase in FGF21 concentrations were associated with higher risk of glycemic progression (adjusted hazards ratio = 1.09 and 1.18 for tertiles 2 and 3, respectively, P for trend = 0.01), even after adjusting for ALT enzyme activity. This association was statistically significant in the fenofibrate group only (P = 0.01).

CONCLUSIONS

Higher baseline and fenofibrate-induced increase in FGF21 concentrations predict more rapid glycemic progression in type 2 diabetes patients. This association may be partly explained by hepatic function.

Complex association of serum alanine aminotransferase with the risk of future cardiovascular disease in type 2 diabetes

BACKGROUND AND AIMS

We aimed to determine the prospective association between baseline serum levels of alanine aminotransferase (ALT) and the incident cardiovascular disease (CVD) in people with type 2 diabetes.

METHODS

In an open cohort setting, people with type 2 diabetes were followed for their first ever CVD presentation from 1995 to 2015. Statistical methods included Cox regression analysis for reporting of hazard ratios (HRs), artificial neural network modelings, and risk reclassification analyses.

RESULTS

We found a nearly constant CVD hazard with baseline serum ALT levels below the 30 IU/L mark, whereas baseline serum ALT levels ≥ 30 IU/L remained an independent predictor of lower CVD rates in patients with type 2 diabetes in the final multivariate Cox proportional hazards regression model (HR: 0.204, 95%CI [0.060-0.689], p_{for trend} value = 0.006). Age, male gender and fasting plasma insulin levels independently predicted baseline serum ALT ≥ 30 IU/L among the population cohort. Augmentation of serum ALT into the weighted Framingham risk score resulted in a considerable net reclassification improvement (NRI) of coronary heart disease (CHD) risk prediction in the study population (NRI = 9.05% (8.01%-10.22%), p value < 0.05).

CONCLUSIONS

Serum ALT could successfully reclassify about 9% of the population with type 2 diabetes across the CHD-affected and CHD-free categories. Overall, our findings demonstrate a complex and nonlinear relationship for the risk of future CVD by baseline serum ALT levels in patients with type 2 diabetes. Further studies are warranted to confirm whether this complex association could be translated into a clearly visible U or J-shaped figure.