Validation of the Friedewald formula for the determination of low-density lipoprotein cholesterol in renal transplant recipients

Association of Non-Insulin-Based Insulin Resistance Indices with Risk of Incident Prediabetes and Diabetes in a Chinese Rural Population: A 12-Year Prospective Study

OBJECTIVE

Three non-insulin-based insulin resistance (IR) indices, ie, triglyceride-glucose (TyG) index, triglyceride-to-high-density lipoprotein cholesterol (TG/HDL-C) ratio, and metabolic score for IR (METS-IR), were considered powerful and simplified alternatives for IR. However, evidence for the association between the three IR indices and incident type 2 diabetes mellitus (T2DM), especially impaired fasting glucose (IFG), remains limited. Therefore, this study aimed to explore the association among IR indices, incident IFG, and T2DM in a rural population cohort.

METHODS

We analyzed data from 2209 adults (aged 24-75 years) at baseline and from 1205 normoglycemic participants who were followed up. Cox proportional hazards models were used to evaluate the associations between the three indices and IFG or T2DM. Restricted cubic spline curves based on the Cox regression model were used to examine the association between baseline indices and incident T2DM.

RESULTS

For the baseline data, logistic analyses demonstrated that the TyG index, TG/HDL-C ratio, and METS-IR had a significantly positive correlation with IFG or T2DM after multivariable adjustment. During a median follow-up of 12.17 years, 157 incident cases of IFG and 97 incident cases of T2DM were noted. The risk of T2DM, but not IFG, was strongly associated with the baseline TyG index in the adjusted model, and participants with the TyG index in the third tertile had a higher risk of developing T2DM (adjusted hazards ratio, 2.84; 95% confidence intervals, 1.26-6.37; p for trend <0.001) than those in the lowest tertile (reference). Moreover, a linear relationship was observed between the TyG index and T2DM incidence. The TG/HDL-C ratio and METS-IR had no significant relationship with the risk of IFG or T2DM.

CONCLUSION

The TyG index is more useful than the TG/HDL-C ratio and METS-IR in predicting T2DM in the normoglycemic population.

Comparison of various formulae for estimating low-density lipoprotein cholesterol by a combination of ages and genders in Taiwanese adults

Background

The accuracy and precision of the Friedewald formula for estimating low-density lipoprotein cholesterol (LDL-C) is questionable. Although other formulae have been developed, only a few studies compare them. Thus, we compared the efficiencies of various formulae, based on the age and gender of adults, to determine which ones yield more accurate estimations in terms of mean squared error, and which formulae underestimated and overestimated LDL-C performance.

Methods

This study compares various formulae in terms of mean squared error (MSE), as well as underestimation and overestimation of LDL-C concentrations, using subjects of various ages and both genders. Six groups were examined in this study based on age and gender: males 20–44 years old, 45–64, and 65 and above, and females in the same three age ranges.

Results

The results show that the Friedewald formula has relatively low accuracy, and while its performance among older (aged 45 and above) women with triglyceride concentrations ≤ 400 mg/dL is better than that with other groups, it is still more inaccurate than the other formulae. In terms of prediction errors and mean squared errors, Tsai’s formula (TF) and a calibrated TF provide the most accurate results with regard to the LDL-C concentration. Moreover, based on a cross-validation of age and gender, these two formulae provide highly accurate results for the LDL-C concentrations of all the studied groups, except for women aged 20–44 years.

Conclusions

Based on the experimental results, this study provides a set of benchmarks for the formulae used in LDL-C tests when considering the factors of age and gender. Therefore, it is a valuable method for providing formula benchmarking.

Edible dry bean consumption (Phaseolus vulgaris L.) modulates cardiovascular risk factors and diet-induced obesity in rats and mice

Pulses are grain legumes that have sustained the civilisations of the world throughout their development; yet this staple food crop has fallen into disuse, particularly in Westernised societies, and decreased consumption parallels increased prevalence of CVD. The objective of the present study was to identify mechanisms that account for the cardioprotective activity of dry bean (Phaseolus vulgaris L.), one of the four primary pulse crops, which is widely produced and consumed globally. Laboratory assays that can be used for in vivo screening of dry beans and other pulses to identify those with the greatest potential to benefit human health are also reported. Sprague–Dawley rats and a diet-induced obesity model in C57Bl/6 mice were used to assess the effect of cooked dry bean incorporated into a purified diet formulation on plasma lipids and hepatic proteins involved in the regulation of lipid biosynthesis. In both animal species, short-term feeding of a bean-containing diet reduced plasma total cholesterol and LDL-cholesterol without affecting HDL-cholesterol or total TAG. Mechanisms associated with cholesterol catabolism and excretion are the likely targets of the bean effect. Unexpectedly, bean-fed obese mice experienced weight loss as well as an improved plasma lipid profile within a 12 d time frame. These findings support the use of short-term (7–14 d) assays to investigate mechanisms that account for the cardioprotective and weight regulatory effects of dry bean and to screen dry bean germplasm resources for types of bean with high protective activity. These same assays can be used to identify the bioactive components of bean that account for the observed effects.

Effect of dietary patterns differing in carbohydrate and fat content on blood lipid and glucose profiles based on weight-loss success of breast-cancer survivors

INTRODUCTION

Healthy body weight is an important factor for prevention of breast cancer recurrence. Yet, weight loss and weight gain are not currently included in clinical-practice guidelines for posttreatment of breast cancer. The work reported addresses one of the questions that must be considered in recommending weight loss to patients: does it matter what diet plan is used, a question of particular importance because breast cancer treatment can increase risk for cardiovascular disease.

METHODS

Women who completed treatment for breast cancer were enrolled in a nonrandomized, controlled study investigating effects of weight loss achieved by using two dietary patterns at the extremes of macronutrient composition, although both diet arms were equivalent in protein: high fat, low carbohydrate versus low fat, high carbohydrate. A nonintervention group served as the control arm; women were assigned to intervention arms based on dietary preferences. During the 6-month weight-loss program, which was menu and recipe defined, participants had monthly clinical visits at which anthropometric data were collected and fasting blood was obtained for safety monitoring for plasma lipid profiles and fasting glucose. Results from 142 participants are reported.

RESULTS

Adverse effects on fasting blood lipids or glucose were not observed in either dietary arm. A decrease in fasting glucose was observed with progressive weight loss and was greater in participants who lost more weight, but the effect was not statistically significant, even though it was observed across both diet groups (P = 0.21). Beneficial effects of weight loss on cholesterol (4.7%; P = 0.001), triglycerides (21.8%; P = 0.01), and low-density lipoprotein (LDL) cholesterol (5.8%; P = 0.06) were observed in both groups. For cholesterol (P = 0.07) and LDL cholesterol (P = 0.13), greater reduction trends were seen on the low-fat diet pattern; whereas, for triglycerides (P = 0.01) and high-density lipoprotein (HDL) cholesterol (P = 0.08), a decrease or increase, respectively, was greater on the low-carbohydrate diet pattern.

CONCLUSIONS

Because an individual's dietary preferences can affect dietary adherence and weight-loss success, the lack of evidence of a negative effect of dietary pattern on biomarkers associated with cardiovascular risk is an important consideration in the development of breast cancer practice guidelines for physicians who recommend that their patients lose weight. Whether dietary pattern affects biomarkers that predict long-term survival is a primary question in this ongoing clinical trial.