Haemostatic factors, lipoproteins and long-term mortality in a multi-ethnic population of Gujarati, African-Caribbean and European origin

Serum apolipoproteins and mortality risk: evidence from observational and Mendelian randomization analyses

BACKGROUND

Apolipoproteins (APOs) have emerged as significant players in lipid metabolism that affects the risk of chronic disease. However, the impact of circulating APO concentrations on premature death remains undetermined.

OBJECTIVES

This study aimed to investigate the associations of serum APOs with all-cause, cardiovascular disease (CVD)-related, and cancer-related mortality.

METHODS

We included 340,737 participants who had serum APO measurements from the UK Biobank. Restricted cubic splines and multivariable Cox regression models were used to assess the associations between APOs and all-cause and cause-specific mortality by computing hazard ratios (HRs) and 95% confidence intervals (CIs). Based on 1-sample Mendelian randomization (MR) design, including 398,457 participants of White ancestry who had genotyping data from the UK Biobank, we performed instrumental variable analysis with 2-stage least squares regression to assess the association between genetically predicted APOs and mortality.

RESULTS

After adjusting for potential confounders including high-density and low-density lipoprotein particles, we observed nonlinear inverse relationships of APOA1 with all-cause, CVD-related, and cancer-related mortality (P-nonlinear < 0.001). By contrast, positive relationships were observed for APOB and all-cause (P-nonlinear < 0.001), CVD-related (P-linear < 0.001), and cancer-related (P-linear = 0.03) mortality. MR analysis showed consistent results, except that the association between APOB and cancer mortality was null. Furthermore, both observational and MR analyses found an inverse association between APOA1 and lung cancer-related mortality (HR comparing extreme deciles: 0.46; 95% CI: 0.26, 0.80; and HR: 0.78; 95% CI: 0.63, 0.97, respectively).

CONCLUSIONS

Our findings indicate that circulating APOA1 has potential beneficial effects on all-cause, CVD-related, and lung cancer-related death risk, whereas APOB may confer detrimental effects on all-cause and CVD-related death risk.

Evaluation of Factor VIII as a Risk Factor in Indian Patients with DVT

Introduction. Elevated factor VIII population in the Indian population has not been studied as a possible risk factor for deep vein thrombosis (DVT). High factor VIII level is considered a predisposing factor for DVT and its recurrence. However it is known to vary between populations and its exact role in the etiopathogenesis of thrombophilia remains unknown. Material and Methods. Factor VIII levels of patients with DVT who had undergone a prothrombotic workup as a part of their workup was compared to normal age matched controls in a 1 : 3 ratio. Results. There were 75 patients with DVT who had undergone a prothrombotic workup in the course of their treatment for lower limb DVT. In these, 64% had levels of factor VIII more than 150 as compared to 63% of normal controls (p > 0.05, not significant). Conclusion. Elevated factor VIII in the Indians may not be associated with the same thrombotic risk as seen in the West. We find a variation in the levels of factor VIII with a different “normal” than what is reported in other populations. This needs further study to elucidate the role of factor VIII in the evaluation and treatment of thrombophilia.

Circulating Inflammatory and Hemostatic Biomarkers are Associated with All-Cause Death and Cancer Death in a Population of Community-Dwelling Japanese: the Tanushimaru Study

BACKGROUND

In patients with cardiovascular diseases, inflammatory and hemostatic biomarkers are significant indicators of prognosis. We investigated whether circulating inflammatory and hemostatic biomarkers were predictive markers for all-cause death and cancer death in a population of community-dwelling Japanese.

METHODS

We studied 1,920 healthy Japanese adults who underwent health examinations in 1999. Those who reported a history of inflammatory diseases and malignancy on a baseline questionnaire were excluded. Inflammatory and hemostatic biomarkers were measured in the remaining 1,862 participants, who were followed up periodically for 10 years. Multivariate proportional hazards regression analysis was used to estimate all-cause and cancer mortality.

RESULTS

A total of 258 participants died during follow-up: 87 from cancer, 38 from cerebro-cardiovascular diseases, and 133 from other diseases. Mean C-reactive protein (CRP) levels at baseline were significantly higher in decedents than in survivors. Mean von Willebrand factor (vWF) levels at baseline were significantly higher in decedents than in survivors. The Cox proportional hazards model after adjustments for age and sex showed that CRP (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.06-1.51) and vWF (HR, 1.01; 95% CI, 1.00-1.01) were independent predictors of all-cause death. CRP (HR, 1.40; 95% CI, 1.06-1.86) and vWF (HR, 1.01; 95% CI, 1.00-1.02) were also independent predictive markers for cancer death.

CONCLUSIONS

Serum CRP and vWF were predictors of all-cause death and cancer death in the population of community dwelling Japanese.

Evidence that multiple defects in lipid regulation occur before hyperglycemia during the prodrome of type-2 diabetes

BACKGROUND

Blood-vessel dysfunction arises before overt hyperglycemia in type-2 diabetes (T2DM). We hypothesised that a metabolomic approach might identify metabolites/pathways perturbed in this pre-hyperglycemic phase. To test this hypothesis and for specific metabolite hypothesis generation, serum metabolic profiling was performed in young women at increased, intermediate and low risk of subsequent T2DM.

METHODS

Participants were stratified by glucose tolerance during a previous index pregnancy into three risk-groups: overt gestational diabetes (GDM; n = 18); those with glucose values in the upper quartile but below GDM levels (UQ group; n = 45); and controls (n = 43, below the median glucose values). Follow-up serum samples were collected at a mean 22 months postnatally. Samples were analysed in a random order using Ultra Performance Liquid Chromatography coupled to an electrospray hybrid LTQ-Orbitrap mass spectrometer. Statistical analysis included principal component (PCA) and multivariate methods.

FINDINGS

Significant between-group differences were observed at follow-up in waist circumference (86, 95%CI (79-91) vs 80 (76-84) cm for GDM vs controls, p<0.05), adiponectin (about 33% lower in GDM group, p = 0.004), fasting glucose, post-prandial glucose and HbA1c, but the latter 3 all remained within the 'normal' range. Substantial differences in metabolite profiles were apparent between the 2 'at-risk' groups and controls, particularly in concentrations of phospholipids (4 metabolites with p ≤ 0.01), acylcarnitines (3 with p ≤ 0.02), short- and long-chain fatty acids (3 with p<  = 0.03), and diglycerides (4 with p ≤ 0.05).

INTERPRETATION

Defects in adipocyte function from excess energy storage as relatively hypoxic visceral and hepatic fat, and impaired mitochondrial fatty acid oxidation may initiate the observed perturbations in lipid metabolism. Together with evidence from the failure of glucose-directed treatments to improve cardiovascular outcomes, these data and those of others indicate that a new, quite different definition of type-2 diabetes is required. This definition would incorporate disturbed lipid metabolism prior to hyperglycemia.