Serum lipid profile as a tool to predict incident diabetes: Is it a wishful thinking?

Variability, Mean, and Baseline Values of Metabolic Parameters in Predicting Risk of Type 2 Diabetes

CONTEXT

The effect of baseline (B) and alteration of metabolic parameters (MPs), including plasma glucose (PG) testing, insulin resistance surrogates, and lipid profile and their mutual interactions on the development of type 2 diabetes mellitus (T2DM), has not been investigated systematically.

OBJECTIVE

To access the association of the past variability (V), past mean (M), and B values of various MPs and their mutual interaction with the risk of T2DM.

METHODS

A community-based, longitudinal analysis was conducted using the Korean Genome and Epidemiology Study comprising 3829 nondiabetic participants with completed MPs measurements during 3 biannually visits who were followed over the next 10 years. Outcomes included the incidence of T2DM during follow-up.

RESULTS

Among predictors, PG concentrations measured during the oral glucose tolerance test were the most prominent T2DM determinants, in which the M of the average value of fasting PG (FPG), 1-hour, and 2-hour PGs had the strongest discriminative power (hazard ratios and 95% CI for an increment of SD: 3.00 (2.5-3.26), AUC: 0.82). The M values of MPs were superior to their B and V values in predicting T2DM, especially among postload PGs. Various mutual interactions between indices and among MPs were found. The most consistent interactants were the M values of high-density lipoprotein cholesterol and the M and V values of FPG. The findings were similar in normal glucose tolerance participants and were confirmed by sensitivity analyses.

CONCLUSION

Postload PG, past alteration of measurements, and mutual interactions among indices of MPs are important risk factors for T2DM development.

The Relationship of 25(OH)D3 with Diabetes Mellitus and the Mediation Effect of Lipid Profile in Chinese Rural Population of Henan Province

Background and Objectives: Studies suggest that vitamin D is involved in the development of type 2 diabetes mellitus (T2DM) and influences serum lipids levels, while lipid disorders are also closely related to T2DM. This study attempts to explore the complex relationship of serum 25(OH)D3, serum lipids, and T2DM among Chinese population. Materials and Methods: A cross-sectional study was carried out among 2326 subjects. The chi-square (χ2) test was applied to compare the prevalence of T2DM or dyslipidemia between two serum 25(OH)D3 levels. Linear regression was applied to analyze the correlation between serum lipids and 25(OH)D3 contents. Univariate and logistic analysis were used to explore the relationship between two lipid levels and T2DM. Mediation analysis was used to explore whether serum lipids mediate the relationship between two serum 25(OH)D3 levels and T2DM. Results: Compared to subjects with 25(OH)D3 ≥ 30 ng/mL, subjects with 25(OH)D3 < 30 ng/mL were higher in the prevalence of T2DM. The occurrences of high TG and low HDL-C were significantly higher in vitamin D deficiency and insufficiency than those in vitamin D sufficiency. Serum 25(OH)D3 content showed a reverse correlation with TC, TG, and LDL-C, but positive correlation with HDL-C. The odds ratios (ORs) (95% confidence intervals, 95%CI) of T2DM by comparing TG ≥ 2.26 mmol/L vs. TG < 2.26 mmol/L and HDL-C < 1.04 mmol/L vs. HDL-C ≥ 1.04 mmol/L in all participants were 2.48 (1.94-3.18) and 1.37 (1.07-1.75), respectively. Serum TG or HDL-C level partially mediated the relationship between two 25(OH)D3 level and T2DM. Conclusions: Serum 25(OH)D3 < 30 ng/mL seems to be associated with T2DM or dyslipidemia (high TG and low HDL-C) in our study, but there is still no proof of a cause-effect relationship. Moreover, serum TG or HDL-C level partially mediated the relationship between 25(OH)D3 levels and T2DM.

HDL associates with insulin resistance and beta-cell dysfunction in South Asian families at risk of type 2 diabetes

OBJECTIVE

Dyslipidemia precedes type 2 diabetes (T2D) and worsens with increasing glucose intolerance. First degree relatives of T2D patients have an increased risk to develop dyslipidemia and glucose intolerance. The aim of the present study was to assess the relation between the development of dyslipidemia and glucose intolerance in first-degree relatives of T2D patients.

RESEARCH DESIGN AND METHODS

Fasting lipoprotein profiles were determined by density gradient ultracentrifugation in T2D patients and their first-degree relatives (42 Caucasians and 33 South Asians), and in 29 normoglycemic controls from non-T2D families. Glucose tolerance, insulin sensitivity index (ISI) and insulin disposition index (DI) were assessed by an extended, frequently sampled oral glucose tolerance test (OGTT), and fractional insulin synthesis rate (FSR) was measured by ¹³C-leucine enrichment in urinary C-peptide during the OGTT.

RESULTS

Of the first-degree relatives, 40, 16 and 19 had NGT, prediabetes and T2D, respectively. NGT family members had lower plasma HDL-cholesterol (HDLC) (1.34 ± 0.07 vs 1.58 ± 0.06 mmol/L; p = 0.015), HDL₂-C (0.41 ± 0.05 vs 0.57 ± 0.05 mmol/L; p = 0.021) and HDL₃-C (0.62 ± 0.03 vs 0.72 ± 0.02 mmol/L; p = 0.043) than controls. HDL₂-C levels tended to decrease with increasing glucose intolerance state. In South Asians, buoyant LDL-C levels decreased with increasing glucose intolerance state (p = 0.006). In South Asian families, HDL-C correlated with both ISI and DI (β 0.42; p = 0.04 and β 0.53; p = 0.01, respectively), whereas HDL₂-C and HDL₃-C levels correlated with DI (β 0.64; p = 0.002 and β 0.57; p = 0.005, respectively). HDL₂-C and plasma triglyceride correlated with FSR (β 0.48; p = 0.033 and β -0.50; p = 0.029, respectively).

CONCLUSIONS

Low HDL₂-C and HDL₃-C levels are present in NGT first-degree relatives of T2D patients, and HDL₂-C tend to decrease further with increasing glucose intolerance. In South Asian families HDL₂-C and HDL₃-C levels linked predominantly to deteriorating beta cell function.