Association of insulin levels with lipids and lipoproteins in elderly Japanese-American men

Elevated serum triglyceride predicts recurrence of colorectal polyps in patients with advanced adenomas

Background

Recurrence of colorectal polyps is common and impacted by various factors. This study was performed to explore the association between lipid profiles and recurrence of colorectal polyps.

Methods

This study retrospectively analyzed the lipid profiles of 435 patients who underwent colonoscopy with removal of colorectal polyps and assessed recurrence of polyps by follow-up colonoscopy. Multivariate regression logistic analysis was used to evaluate the association between lipid profiles and polyp recurrence.

Results

During the 1.5-year follow-up, recurrence of colorectal polyps was observed in 135 of 435 patients (30.34%). Patients with recurrent polyps showed a higher level of triglycerides (P = 0.006) and lower levels of high-density lipoprotein cholesterol (P = 0.008) and apolipoprotein A1 (P = 0.033). The multivariate regression logistic model suggested that an elevated triglyceride level was an independent risk factor for polyp recurrence (odds ratio, 1.55; 95% confidence interval, 1.02–2.35; P = 0.039) in patients with advanced adenoma.

Conclusions

Lipid profiles are associated with recurrence of colorectal polyps. An elevated triglyceride level is an independent risk predictor of polyp recurrence in patients with advanced adenoma.

A simple scoring model for advanced colorectal neoplasm in asymptomatic subjects aged 40-49 years

Background

Limited data are available for advanced colorectal neoplasm in asymptomatic individuals aged 40–49 years. We aimed to identify risk factors and develop a simple prediction model for advanced colorectal neoplasm in these persons.

Methods

Clinical data were collected on 2781 asymptomatic subjects aged 40–49 years who underwent colonoscopy for routine health examination. Subjects were randomly allocated to a development or validation set. Logistic regression analysis was used to determine predictors of advanced colorectal neoplasm.

Results

The prevalence of overall and advanced colorectal neoplasm was 20.2 and 2.5% respectively. Older age (45–49 years), male sex, positive serology of Helicobacter pylori, and high triglyceride and low high-density lipoprotein (HDL) levels were independently associated with an increased risk of advanced colorectal neoplasm. BMI (body mass index) was not significant in multivariable analysis. We developed a simple scoring model for advanced colorectal neoplasm (range 0–9). A cutoff of ≥4 defined 43% of subjects as high risk for advanced colorectal neoplasm (sensitivity, 79%; specificity, 58%; area under the receiver operating curve = 0.72) in the validation datasets.

Conclusion

Older age (45–49 years), male sex, positive serology of H. pylori, high triglyceride level, and low HDL level were identified as independent risk factors for advanced colorectal neoplasm.

Association between Obesity, Serum Lipids, and Colorectal Polyps in Old Chinese People

Background. Colorectal cancer mostly arises from the polyps of colon. The aim of our study was to examine the association of body mass index (BMI) and serum lipids with the colorectal polyps in old Chinese people. Methods. The risk of developing colorectal polyps was studied in 244 subjects (212 men and 32 women, 74.63 ± 11.63 years old) who underwent colonoscopy for the first time from January 2008 to July 2012 at the Navy General Hospital, Beijing, China. According to the results of colonoscopy, all the subjects were divided into 112 normal control, 38 right colorectal polyps, 53 left colorectal polyps, and 41 both right and left colorectal polyps groups. The total plasma cholesterol, plasma triglyceride, plasma creatinine concentration, blood urinary nitrogen, and fasting glucose were determined using a multichannel analyzer. Results. There were significant differences among normal control, right colorectal polyps, left colorectal polyps, and both right and left polyps groups, which were the BMI, total cholesterol, triglycerides, creatinine, and urinary nitrogen. In binary logistic regression analysis, there were two risk factors associated with the occurrence of colorectal polyps, which included BMI and systolic blood pressure. Conclusions. Colorectal polyps were significantly associated with increased BMI, total cholesterol, and triglycerides levels.

The association of serum lipids with colorectal adenomas

OBJECTIVES

There is suggestive but sparse evidence that dyslipidemia is associated with colorectal neoplasms. We investigated the association of serum lipid and apolipoprotein concentrations with the prevalence of colorectal adenomas.

METHODS

Cross-sectional study of 19,281 consecutive participants aged 40-79 years undergoing screening colonoscopy at the Center for Health Promotion of the Samsung Medical Center in Korea from January 2006 to June 2009.

RESULTS

We identified 5,958 participants with colorectal adenomas (30.9%), including 5,504 (28.5%) with non-advanced adenomas and 454 (2.4%) with advanced adenomas. The adjusted relative prevalence ratios (aRPRs) comparing the fourth with the first quartiles of serum triglycerides were 1.35 (95% confidence interval (CI) 1.20-1.52; P trend<0.001) for non-advanced adenomas and 1.45 (95% CI 1.02-2.06; P trend=0.005) for advanced adenomas. Higher levels of high-density lipoprotein (HDL) cholesterol and apolipoprotein A-1 (ApoA-1) were significantly associated with 12% (Q4 vs. Q1 aRPR 1.12; 95% CI 1.00-1.26; P trend=0.049) and 17% (Q4 vs. Q1 aRPR 1.17; 95% CI 1.04-1.31; P trend=0.004) higher prevalence of non-advanced adenoma. There was also a non-significant association between higher levels of low-density lipoprotein (LDL) cholesterol (Q4 vs. Q1 aRPR 1.22; 95% CI 0.91-1.66; P trend= 0.12) and apolipoprotein B (ApoB) (Q4 vs. Q1 aRPR 1.32; 95% CI 0.94-1.83; P trend=0.07) with higher prevalence of advanced adenoma. There was no association between total cholesterol levels with colorectal adenoma.

CONCLUSIONS

In this large cross-sectional study, higher levels of serum triglycerides were significantly associated with an increasing prevalence of both non-advanced and advanced colorectal adenomas, while higher levels of ApoA-1 and HDL cholesterol were significantly associated with an increasing prevalence of non-advanced adenomas.

The association of serum lipids with the histological pattern of rectosigmoid adenoma in Taiwanese adults

BACKGROUND

The mortality rate of colorectal cancer ranks third behind lung and hepatic cancer in Taiwan. Colorectal cancer mostly arises from adenomatous polyps of left colon. The aim of our study was to examine the association of serum lipids with the histological pattern of rectosigmoid adenoma.

METHODS

There were 2,506 eligible examinees aged 20 and above who underwent sigmoidoscopy as a screening examination in National Cheng Kung University Hospital between January 2003 and October 2006. They were classified into three groups: tubular adenoma (333 subjects), villous-rich (tubulovillous/villous) adenoma (53 subjects) and normal (2,120 subjects). We defined high total cholesterol (TC) as a level ≧200 mg/dl, low high-density lipoprotein cholesterol (HDL-C) as a level <40 mg/dL, and high triglyceride (TG) as a level ≧200 mg/dl according to the third report of the National Cholesterol Education Program expert panel on detection, evaluation, and treatment of high blood cholesterol in adults. Adenoma histology was classified as tubular, tubulovillous and villous according to the proportion of villous part.

RESULTS

Among the study population, 333 subjects (13.3%) had tubular adenomas and 53 subjects (2.1%) had villous-rich adenomas. The odds ratio (OR) for villous-rich adenoma in subjects with TG≧200 mg/dL compared to those with TG < 200 mg/dL was 3.20 (95% confidence interval [CI]:1.71-6.01), after adjusting for age, gender, general obesity, central obesity, diabetes, hypertension, smoking, and alcohol consumption. If further taking high TC and low HDL-C into consideration, the OR was 4.42 (95% CI:2.03-9.63).

CONCLUSIONS

Our study showed that subjects with high serum TG tended to have a higher risk of tubulovillous/villous adenoma in rectosigmoid colon. Therefore, reducing the serum TG level might be one method to prevent the incidence of colorectal cancer.

Menopause, insulin resistance, and risk factors for cardiovascular disease

OBJECTIVE

In this retrospective analysis of the European Group for the Study of Insulin Resistance database, a clamp data pooling project, a cardiovascular risk score (CVS) was assessed to verify whether hyperinsulinemia and/or insulin resistance were independent cardiovascular risk factors and to investigate how menopause affected CVS and insulin resistance.

DESIGN

Information was obtained on whole-body glucose uptake (M), determined by the euglycemic hyperinsulinemic clamp technique, normalized by fat-free mass (FFM), and insulin concentration (I) at a steady state. Body composition was estimated using a labeled water technique or bioimpedance. Other parameters measured included blood pressure, lipid levels, and waist-to-hip ratio. CVS was computed using a structural equation model that included age, body mass index, blood lipids, and blood pressure. The study population included 523 normal and overweight patients. Women were grouped according to fertility status, and men, according to age (cutoff 50 y).

RESULTS

M/kg(FFM)/I significantly decreased after menopause (12.41 +/- 3.40 vs 10.96 +/- 3.68; P < 0.01) and in men 50 years and older (11.39 +/- 3.47 vs 10.32 +/- 3.77 micromol x min(-1) x kg(-1) x microUI/mL; P < 0.02). CVS was lowest in fertile women (-0.414 +/- 0.57 vs 0.107 +/- 0.43; P < 0.0001) and highest in men 50 years and older (0.045 +/- 0.455 vs 0.257 +/- 0.51; P < 0.001). CVS significantly correlated with M/kg(FFM)/I in men 49 years and younger (r(o) = -0.27, P < 0.0001) and 50 years and older (r(o) = -0.38, P < 0.0001) and with fasting insulin in fertile women (r(o) = -0.29, P < 0.01) and in the other groups (r(o) ranging from 0.37 to 0.45, P < 0.0001).

CONCLUSIONS

Menopause does not seem to strictly relate to a decrease in insulin sensitivity as postmenopausal women had the same insulin sensitivity as age-matched men. In the population studied, the best predictor of CVS was fasting insulin rather than insulin sensitivity.

Risk factor groupings related to insulin resistance and their synergistic effects on subclinical atherosclerosis: the atherosclerosis risk in communities study

The extent to which groupings of insulin resistance-related cardiovascular risk factors synergize to produce atherosclerosis beyond what is expected from their additive effects is uncertain. The objective of this study was to measure interactions among groupings of the features of the insulin resistance syndrome (IRS) on carotid intimal-medial thickness (IMT). This cross-sectional study used baseline data from the Atherosclerosis Risk in Communities Study on 11,790 adults aged 45-64 years without diagnosed diabetes, treated dyslipidemia, or coronary heart disease. The main outcome was carotid IMT, assessed using B-mode ultrasound. The excess carotid IMT attributable to each IRS grouping was determined using multiple linear regression models. There were 57 possible combinations of six IRS components (hypertension, hyperinsulinemia, obesity, hypertriglyceridemia, low HDL cholesterol, and hyperglycemia). In multivariate analysis, 29 of the 57 groupings were associated with excess carotid IMT. Individuals with all six IRS components had the greatest excess IMT compared with those without this grouping (71 micro m; 95% CI 40-102 micro m). The groupings most strongly associated with excess carotid IMT included hypertension and hypertriglyceridemia. Interventions aimed at ameliorating the IRS may produce reductions in atherosclerotic risk beyond that predicted by treatment of individual IRS-related risk factors.

Homeostasis model assessment of insulin resistance in relation to the incidence of cardiovascular disease: the San Antonio Heart Study

OBJECTIVE

The prospective association between insulin levels and risk of cardiovascular disease (CVD) is controversial. The objective of the present study was to investigate the relationship of the homeostasis model assessment of insulin resistance (HOMA-IR), as well as insulin levels, with risk of nonfatal and fatal CVD over the 8-year follow-up of the San Antonio Heart Study.

RESEARCH DESIGN AND METHODS

Between 1984 and 1988, randomly selected Mexican-American and non-Hispanic white residents of San Antonio participated in baseline examinations that included fasting blood samples for glucose, insulin, and lipids, a glucose tolerance test, anthropometric measurements, and a lifestyle questionnaire. Between 1991 and 1996, 2,569 subjects who were free of diabetes at baseline were reexamined using the same protocol.

RESULTS

Over the follow-up period, 187 subjects experienced an incident cardiovascular event (heart attack, stroke, heart surgery, angina, or CVD death). Logistic regression analysis indicated that risk of a CVD event increased across quintiles of HOMA-IR after adjustment for age, sex, and ethnicity (P for trend <0.0001; quintile 5 vs. quintile 1, odds ratio [OR] 2.52, 95% CI 1.46-4.36). Additional adjustment for LDL, triglyceride, HDL, systolic blood pressure, smoking, alcohol consumption, exercise, and waist circumference only modestly reduced the magnitude of these associations (P for trend 0.02; quintile 5 vs. quintile 1, OR 1.94, 95% CI 1.05-3.59). Furthermore, there were no significant interactions between HOMA-IR and ethnicity, sex, hypertension, dyslipidemia, glucose tolerance (impaired glucose tolerance versus normal glucose tolerance), or obesity. The magnitude and direction of the relationship between insulin concentration and incident CVD were similar.

CONCLUSIONS

We found a significant association between HOMA-IR and risk of CVD after adjustment for multiple covariates. The topic remains controversial, however, and additional studies are required, particularly among women and minority populations.