C-Peptide and cardiovascular risk factors among young adults in a southern Brazilian cohort

Serum C-peptide level and the risk of cardiovascular diseases mortality and all-cause mortality: a meta-analysis and systematic review

Aims and background

Recently, the serum of C-peptide has been the focus of researchers as a possible predictor of mortality. However, the possible association of serum C-peptide with cardiovascular diseases (CVDs) mortality and all-cause mortality has not been clearly identified. This meta-analysis aimed to assess the relationship between serum C-peptide and the risk of CVDs mortality and all-cause mortality.

Methods

A comprehensive and systematic search was performed in various important databases, including the PubMed, Web of Science, and Scopus to find relevant studies up to November 2022. The reported hazard ratio (HR) [95% confidence interval (CI)] for all studies was converted into log HR, and their SD was calculated. Then to compute the pooled HR, the random-effects model with inverse variance weighting method was performed.

Results

Twenty-three studies were included in the meta-analysis. Fourteen studies reported HR for all-cause mortality, and nine studies for CVDs-related mortality. The pooled results indicate a significant association between serum C-peptide and the risk of all-cause mortality (HR: 1.22; 95% CI: 1.12-1.32, I²= 76.8%; P-value < 0.001). Also, higher serum C-peptide was related to the increased risk of CVDs mortality (HR: 1.38; 95% CI: 1.08-1.77, I²= 81.8%; P-value = 0.012).

Conclusions

Our investigation suggested that an increased level of serum C-peptide is associated with a higher risk of both CVDs and all-cause mortality. Further, large-scale studies and sufficient samples are recommended to present a convincing link between C-peptide and the risk of CVDs and all-cause mortality.

Systematic Review Registration

identifier, CRD42022364842.

Adipokine Levels in Men with Coronary Atherosclerosis on the Background of Abdominal Obesity

Background. Obesity is associated with dyslipidemia, and excess body fat is associated with unfavorable levels of adipokines and markers of inflammation. The goal of research. To study the level of adipokines and markers of inflammation, their associations with unstable atherosclerotic plaques in men with coronary atherosclerosis on the background of abdominal obesity. Materials and methods. The study involved 82 men aged 40–77 years with coronary atherosclerosis after endarterectomy from the coronary arteries. We divided all men into two groups: 37 men (45.1%) with unstable atherosclerotic plaques, and 45 men (54.9%) who had stable plaques. Obesity was established at a BMI of ≥30 kg/m2. The levels of adipokines and markers of inflammation in the blood were determined by multiplex analysis. Results. In patients with obesity and unstable plaques, the levels of C-peptide, TNFa and IL-6 were 1.8, 1.6, and 2.8 times higher, respectively, than in patients with obesity and stable plaques. The chance of having an unstable plaque increases with an increase in TNFa by 49% in obese patients and decreases with an increase in insulin by 3% in non-obese patients. Conclusions. In men with coronary atherosclerosis and obesity, unstable atherosclerotic plaques in the coronary arteries are directly associated with the level of TNF-α.

Casual C peptide index: Predicting the subsequent need for insulin therapy in outpatients with type 2 diabetes under primary care

BACKGROUND

Evaluation of residual beta cell function is indispensable in patients with type 2 diabetes as it informs not only diagnoses but also appropriate treatment modalities. However, there is a lack of convenient biomarkers for residual beta cell function. Therefore, we evaluated endogenous insulin level as a biomarker in outpatients who were being treated with insulin therapy and in patients who were introduced to insulin therapy after 4 years.

METHODS

Data of 174 outpatients with type 2 diabetes (50% male) whose glycemia was moderately controlled (glycated A1c 7.3% [5.2%-14.8%]) were reviewed. Twenty patients whose estimated glomerular filtration rate was lower than 30 ml/min/1.73 m² were excluded from the evaluation of endogenous insulin level with both casual C-peptide index (C-CPI) and urinary C-peptide/creatinine ratio (determined at any time, generally 1-2 h after breakfast). Patients were stratified based on the provision of insulin therapy.

RESULTS

C-CPI and UCPCR were significantly lower in the insulin-treated patients than in the insulin-untreated patients (0.9 vs. 2.2, p < 0.0001; 24.7 vs. 75.5, p = 0.0003, respectively). Moreover, C-CPI were significantly lower in the insulin-requiring patients for 4 years than in the insulin-unrequiring patients (1.0 vs. 1.7, p = 0.0184). The multivariate logistic regression analysis revealed that both indicators of insulin secretion influenced the requirement for insulin therapy, but C-CPI could serve as the most convenient and useful biomarker for not only current insulin therapy requirements (p = 0.0002) but also the subsequent requirement for insulin therapy (p = 0.0008).

CONCLUSIONS

C-CPI could be determined easily, and it was found to be a more practical marker for outpatients; therefore, our findings would have critical implications for primary care.

Favourable Changes in C-Peptide, C-Reactive Protein and Lipid Profile, and Improved Quality of Life in Patients with Abnormal Body Mass Index after the Use of Manual Lymphatic Drainage: A Case Series with Three-Month Follow-Up

Aim: to try to assess the effect of manual lymphatic drainage on the biochemical parameters and quality of life of patients with abnormal body mass index. The study included three women, average age 46 years (patient 1 with normal body weight as a control; patient 2: overweight; patient 3 with class 2 obesity). After qualification, physiotherapeutic interview and examination was carried out; the concentrations of glycosylated haemoglobin (HbA1c), C-peptide, high-sensitivity C-reactive protein (hsCRP), lipid profile, and quality of life were also examined. Additionally, in patients with abnormal body mass index, biochemical parameters were monitored for 3 months. Each patient underwent 10 manual lymphatic drainage (MLD) therapy sessions, three times a week for 30 min. In the overweight patient (patient 2), a decrease in the concentration of C-peptide, hsCRP and triglycerides was observed after the series of MLD therapy. An improvement in the quality of life, intestinal motility, and a reduction in the frequency of flatulence were also noted. Moreover, after the therapy, patient 2 reported better sleep and increased vitality. In contrast, in patient 3 (with grade 2 obesity), a decrease in triglyceride levels, but not other biomarkers, was detected after the series of MDL therapy. Additionally, in patient 3, an improvement in the quality of life, an improvement in intestinal peristalsis, and reduction of menstrual pain were observed after MLD therapy. For comparison, in a patient with a normal body weight as a control (patient 1), there were no changes in biochemical parameters or improvement in the quality of life after MLD therapy. Our preliminary research indicates improvement of the concentration C-peptide, lipid profile, a reduction in the inflammation, and improved quality of life in patients with abnormal body mass index after MLD therapy. However, more studies are needed to elucidate the effectiveness of MLD therapy in patients with varying degrees of abnormal body mass index, i.e., from overweight to obesity.

Cholesterol and glucose profiles according to different fasting C-peptide levels: a cross-sectional analysis in a healthy cohort from the Czech Republic

The relationship between glycaemia and lipoprotein metabolism has not been completely clarified, and slight differences may be found between local authors, trials and evaluated parameters. Therefore this cross-sectional study investigated fasting cholesterol and glucose levels along with the determination of atherogenic index in a cohort of healthy individuals from the Czech Republic in relation to their fasting C-peptide levels. Data were collected between 2009 and 2018 and a total of 3189 individuals were stratified by C-peptide reference range (260-1730 pmol/l) into three groups - below (n = 111), within (n = 2952) and above (n = 126). Total, HDL, LDL cholesterol and atherogenic index were used to compare lipoprotein levels by relevant C-peptide concentrations. Participants using the supplements to affect lipid or glycaemia metabolism were excluded from this study. The evaluation of blood parameters in a fasting state included correlations between C-peptide and cholesterols, differences of variances (F-test) and the comparison of lipoprotein mean values (t-test) between the groups created by the C-peptide reference range. Mean values of total (4.9, 5.1, 5.3 mmol/l), LDL (2.6, 3.1, 3.4 mmol/l) cholesterol and atherogenic index (2.1, 2.8, 3.7) were higher with increasing C-peptide levels, whereas HDL was inversely associated with fasting C-peptide concentration. A positive and negative correlation between atherogenic index (rxy = 0.36) and HDL level (rxy = -0.36) with C-peptide values was found. Differences of HDL, LDL and atherogenic index were, in particular, recorded between the groups below and above the reference range of C-peptide (p ≤ 0.001). Considerable differences (p ≤ 0.001) were also observed for the same lipoprotein characteristics between the groups above and within the C-peptide reference. Generally, the type of cholesterol is crucial for the evaluation of specific changes concerning the C-peptide range. Lipoprotein concentrations differ in relation to C-peptide - not only below and above the physiological range, but also inside and outside of it. Conclusions: Fasting levels of cholesterol, plasma glucose, and atherogenic index were strongly associated with fasting C-peptide levels in healthy individuals. Our data suggest that fasting C-peptide could serve as a biomarker for the early detection of metabolic syndrome and/or insulin resistance prior to the manifestation of type 2 diabetes.

Alterations of glycaemia, insulin resistance and body mass index within the C-peptide optimal range in non-diabetic patients

The study focused on changes or cut-offs of glycaemia, insulin resistance and body mass index within the C-peptide reference range (260-1730 pmol/l). The metabolic profile of individuals in the Czech Republic without diabetes (n = 3186) was classified by whiskers and quartiles of C-peptide into four groups with the following ranges: 290-510 (n = 694), 511-710 (n = 780), 711-950 (n = 720) and 951-1560 pmol/l (n = 673). Fasting levels of glucose, insulin, HOMA IR (Homeostasis Model Assessment for Insulin Resistance) and BMI (body mass index) were compared by a relevant C-peptide range. Participants taking medication to control glycaemia were excluded. The evaluation involved correlations between C-peptides and the above parameters, F-test and t-test. Changes in glucose levels (from 5.3 to 5.6 mmol/l) between the groups were lower in comparison to insulin, which reached relatively greater changes (from 4.0 to 14.2 mIU/l). HOMA IR increased considerably with growing C-peptide concentrations (0.9, 1.5, 2.2 and 3.5) and BMI values showed a similar trend (28.3, 31.0, 33.6 and 37.4). Considerable changes were observed for insulin (5.2 mIU/l, 57.8%) and HOMA IR (1.3, 61.3%) between groups with C-peptide ranges of 711-950 and 951-1560 pmol/l. Although correlations involving C-peptide, insulin, glucose and BMI seemed to be non-significant (up to rxy = 0.25), the mean values of insulin, HOMA IR and BMI showed statistically significant changes between all groups with various C-peptide concentrations (p ≤ 0.001). Generally, most important differences appeared in glucose metabolism and body mass index between C-peptide ranges of 711-950 and 951-1560 pmol/l. Absolute and relative changes of C-peptide concentrations are possible to use for the assessment of glucose regulatory mechanism. The spectrum of investigated parameters could be a useful tool to prevent the risks linked with the alterations of glycaemia.