Effect of cellular cholesterol changes on insulin secretion by tumor cell lines

Association of variability in metabolic parameters with the incidence of type 2 diabetes: evidence from a functional community cohort

BACKGROUND

To investigate the association of variability in metabolic parameters such as total cholesterol concentrations (TC), uric acid (UA), body mass index (BMI), visceral adiposity index (VAI) and systolic blood pressure (SBP) with incident type 2 diabetes (T2D) and whether variability in these metabolic parameters has additive effects on the risk of T2D.

METHODS

Based on the Beijing Functional Community Cohort, 4392 participants who underwent three health examinations (2015, 2016, and 2017) were followed up for incident T2D until the end of 2021. Variability in metabolic parameters from three health examinations were assessed using the coefficient of variation, standard deviation, variability independent of the mean, and average real variability. High variability was defined as the highest quartile of variability index. Participants were grouped according to the number of high-variability metabolic parameters. Cox proportional hazards models were performed to assess the hazard ratio (HR) and 95% confidence interval (CI) for incident T2D.

RESULTS

During a median follow-up of 3.91 years, 249 cases of incident T2D were identified. High variability in TC, BMI, VAI and SBP was significantly associated with higher risks of incident T2D. As for UA, significant multiplicative interaction was found between variability in UA and variability in other four metabolic parameters for incident T2D. The risk of T2D significantly increased with the increasing numbers of high-variability metabolic parameters. Compared with the group with low variability for 5 parameters, the HR (95% CI) for participants with 1-2, 3, 4-5 high-variability metabolic parameters were 1.488 (1.051, 2.107), 2.036 (1.286, 3.222) and 3.017 (1.549, 5.877), respectively. Similar results were obtained in various sensitivity analyses.

CONCLUSIONS

High variability of TC, BMI, VAI and SBP were independent predictors of incident T2D, respectively. There was a graded association between the number of high-variability metabolic parameters and incident T2D.

Increased risk for diabetes development in subjects with large variation in total cholesterol levels in 2,827,950 Koreans: A nationwide population-based study

BACKGROUND

Recent studies suggest a role for hyperlipidemia in the development of diabetes. The aim of this study is to analyze the relationship between variations of total cholesterol (TC) levels and the risk for type 2 diabetes development from a Korean nationwide population-based database.

MATERIALS AND METHODS

We examined the General Health Check-up sub-dataset of the Korean National Health Insurance Service (NHIS) of 2,827,950 participants who had at least three health check-ups between 2002 and 2007, and were not reported to have diabetes during that time. The variations of TC levels between the examinations were calculated as follows: [Formula: see text]. The examinees were divided into 10 groups according to TC variation, and the hazard ratio for diabetes development from 2007 to 2013, were analyzed.

RESULTS

During the follow-up period, 3.4% of the participants had developed diabetes. The hazard ratio (HR) for diabetes development relative to the overall risk in the whole study population started to be higher than 1.0 from eighth decile of TC variation. The highest decile group showed an increased HR for diabetes development after adjustment for confounding variables (1.139; 95% confidence interval 1.116~1.163). These results were similar regardless of the use of anti-hyperlipidemic medication and baseline TC levels.

CONCLUSIONS

The participants with a large variation in TC levels showed an increased risk for diabetes development, independent of the use of anti-hyperlipidemic medications. These results suggest a relationship between fluctuations in lipid levels and the development of type 2 diabetes.

Insulin resistance contributes more to the increased risk for diabetes development in subjects with low lipoprotein(a) level than insulin secretion

Background

Recent studies suggest an association between Lipoprotein(a) [Lp(a)] and the development of diabetes mellitus. We analyzed the association between baseline Lp(a) levels and diabetes development after 4 years of follow-up, in a population of apparently healthy Korean subjects.

Methods

A total of 2,536 non-diabetic participants (mean age: 41 years, men: 92%) of a health checkup program were included in the study. Diabetes development was defined by fasting blood glucose ≥126 mg/dL, HbA1c ≥6.5%, and self-reported treatment of diabetes. Homeostasis model assessment (HOMA) indices were used to assess insulin resistance (IR) and insulin secretion (IS). Presence of IR and impaired IS was defined by being in the highest quartile of HOMA-IR and in the lowest quartile HOMA-IS.

Results

After four years, 3.4% of the participants developed diabetes. The odds ratio (OR) of developing diabetes was lowest in the 4^th quartile group of baseline Lp(a) (0.323 [95% CI 0.153–0.685])with the 1^st quartile group as the reference. The subjects with both IR & impaired IS plus baseline Lp(a)<50 mg/dL showed the higher OR for diabetes development compared with those without IR and normal IS as the reference (67.277 [20.218–223.871], and those with IR plus Lp(a)<50 mg/dL showed higher OR for diabetes than in those with impaired IS and Lp(a)<50 mg/dL (3.811 [1.938–7.495] vs. 3.452 [1.620–7.353]).

Conclusions

The subjects with low baseline Lp(a) level showed higher risk for development of diabetes compared with high baseline Lp(a) level, and this was prominent in those with IR than in those with impaired IS.