Histogram-based Sub-classification of Serum Triglycerides and Hypertriglyceridemia Prevalence Across Gender and Age Groups: A Cross-sectional Study

Abstract

Introduction: The ICMR-Indiab study (2014) and National Centres for Environmental Prediction (NCEP) (2001) guidelines recommended a healthy cut-off for serum triglycerides of 50 years. Triglycerides were assayed using an enzymatic method. The histogram was divided into healthy (<150 mg/dL), positively skewed and outlier regions. Sample distribution before and after outlier removal was represented by the histogram and analysed using the Shapiro-Wilk and Jarque-Bera tests. Gender differences were analysed using the Mann-Whitney U test with Statistical Package for Social Sciences (SPSS) software. Results: The number of samples increased with age. In the histogram, the sample number decreased sequentially from the healthy region to the positively skewed and finally to the outlier region across all age groups. The p-value for distributions before the removal of outliers was <0.001. Males had higher mean triglyceride levels, with p-values ranging from <0.001 to 0.029 and exhibited a higher prevalence of hypertriglyceridemia in all groups. The histogram method allowed for the differentiation between the highly prevalent multifactorial moderate hypertriglyceridemia and the rare severe single-gene defects. Conclusion: The study partitioned triglyceride concentrations using a histogram into healthy, positively skewed and outlier regions. The histogram of hypertriglyceridemia can be clinically utilised to differentiate between the highly prevalent, multifactorial moderate hypertriglyceridemia and the rare, severe monogenic hypertriglyceridemia.

Keywords

• hyperlipidemia
• non parametric
• outlier region
• sex factors