Hypertriglyceridemia is associated with insulin levels in adult cystic fibrosis patients

Abstract

Background: Recent studies have identified hypertriglyceridemic cystic fibrosis patients (CF-TG). However, whether hypertriglyceridemia is associated with an altered metabolic profile remains unknown.

Objective: To characterize CF-TG and determine whether triglycerides (TG) levels are associated with metabolic alterations.

Methods: 210 adult CF subjects from the Montreal Cystic Fibrosis Cohort without known diabetes were included in the analysis. All subjects underwent an OGTT to assess glucose tolerance, insulin secretion (insulin AUC) and insulin sensitivity (Stumvoll index). Fasting lipid profiles, pulmonary function (%FEV1) and BMI were determined. Hypertriglyceridemia (TG>1.7mmol/L) was observed in 20 CF patients. These subjects were matched for age, sex and glucose tolerance category with 20 CF patients (CF-normal-TG) and 20 healthy controls that had TG levels below 1.7mmol/L. Pearson correlations were performed in the complete study sample (n=210) to examine the associations between TG levels and other parameters.

Results: The prevalence of hypertriglyceridemia was 9.5%. Compared to CF-normal-TG, CF-TG subjects displayed significantly higher %FEV1, insulin AUC (AUC0-120, AUC0-30, AUC30-120), cholesterol levels and a higher ratio of total cholesterol to HDL-cholesterol. Pearson analysis demonstrated that TG levels were associated with BMI, %FEV1, fasting insulin, insulin AUC0-120 and AUC30-120, Stumvoll index, cholesterol levels and the ratio of total cholesterol to HDL-cholesterol. All these correlations remained significant after correction for BMI except %FEV1.

Conclusion: TG levels are associated with a mild alteration of the metabolic profile. Whether these changes will increase the long-term risk of CF patients in developing cardiometabolic complications remains to be investigated.