High triglycerides to HDL-cholesterol ratio is associated with insulin resistance in normal-weight healthy adults

Abstract

Aim

To evaluate the association between high triglyceride/HDL-cholesterol (TG/HDL-C) ratio and insulin resistance (IR) or hyperinsulinemia after oral glucose tolerance test (OGTT) in normal-weight healthy adults.

Methods

We carried out an analytical cross-sectional study in euthyroid non-diabetic adults, who attended the outpatient service of a private clinic in Lima-Peru from 2012 to 2016. Participants were divided in two groups according to the presence or absence of high TG/HDL-C ratio, IR or hyperinsulinemia after OGTT. TG/HDL-C ratio values ≥ 3 were considered as high. IR was defined as a Homeostasis Model Assessment (HOMA-IR) value ≥ 2.28 and hyperinsulinemia after OGTT as a serum insulin value ≥ 80μU/mL after 120 min of 75-g glucose intake. We elaborated crude and adjusted Poisson generalized linear models to evaluate the association between high TG/HDL-C ratio and IR or hyperinsulinemia after OGTT and reported the prevalence ratio (PR) with their respective 95% confidence intervals (95%CI).

Results

We analyzed the data of 118 individuals. Prevalence of high TG/HDL-C ratio was 17.8% (n = 21) while the prevalence of IR and hyperinsulinemia after OGTT was 24.6% (n = 29) and 17.0% (n = 20), respectively. TG/HDL-C-ratio values were positively correlated with HOMA-IR (r = 0.498; p < 0.01) and serum insulin after OGTT (r = 0.326; p < 0.001). In the adjusted model, high TG/HDL-C ratio was associated with both IR (aPR = 3.16; 95%CI: 1.80–5.77) and hyperinsulinemia after OGTT (aPR = 2.36; 95%CI: 1.20–4.63).

Conclusions

High TG/HDL-C ratio was associated with both IR markers used in our study, appearing to be a clinically useful tool to assess IR in euthyroid normal-weight adults without type 2 diabetes mellitus.

Introduction

Insulin resistance (IR) is considered a complex metabolic disorder [1,2] defined as the inability of insulin to properly ensure the glucose uptake and utilization [3]. IR represents an important clinical condition, as it is strongly associated with different types of cancer [[4], [5], [6], [7]] and several cardiovascular [[8], [9], [10]], metabolic [[11], [12], [13]] and brain disorders [[14], [15], [16]].

To date, the hyperinsulinemic-euglycemic clamp remains as the gold standard for IR [17] and HOMA-IR is the most widely used alternative [18,19]. However, both have some limitations, mainly related to cost, accessibility, reproducibility and replicability [17,[19], [20], [21], [22]]. Thus, in recent years, different studies worldwide have tried to develop and assess new markers for IR [23].

It is known that hypertriglyceridemia and low levels of high density lipoprotein cholesterol (HDL-C) play an important role in the pathogenesis of IR and metabolic syndrome [[24], [25], [26], [27], [28]]. In addition, current literature mentions that it is not uncommon for people with a normal body mass index (BMI) to present metabolic disorders [[29], [30], [31], [32]]. In this sense, the use of lipid markers could be useful for an early and accurate diagnosis of IR, when the two previously mentioned measures are not available.

In Latin America, two studies conducted in adult populations in Mexico [33] and Argentina [34] aimed to assess the performance of the Triglycerides (TG)/HDL-C ratio for IR diagnosis, showing some favourable results. Peru is a country that has been through a nutritional transition during the last years, with an increase in the prevalence of non-communicable diseases [35]. Nevertheless, few studies have been conducted in order to evaluate the performance of surrogate biomarkers for IR [36,37], and this TG/HDL-C ratio still remains unassessed.

For the above mentioned, the objective of the study was to assess the association between high TG/HDL-C ratio and IR or hyperinsulinemia after oral glucose tolerance test (OGTT) in a sample of normal-weight adults.