The obese lipid profile is associated with increased free fatty acids and triacylglycerides. Currently, little is known about the plasma lipid species associated with obesity. In this study, we compared plasma lipid fatty acid (FA) profiles as a function of BMI. Profiling phospholipid (PL) FAs and their respective oxylipids could predict which obese individuals are more likely to suffer from diseases associated with chronic inflammation or oxidative stress. We investigated the relationship between BMI and plasma PL (PPL) FA composition in 126 men using a quantitative gas chromatography analysis. BMI was inversely associated with both PPL nervonic and linoleic acid (LA) but was positively associated with both dihomo-γ-linolenic and palmitoleic acid. Compared to lean individuals, obese participants were more likely to have ω-6 FAs, except arachidonic acid and LA, incorporated into PPLs. Obese participants were less likely to have EPA and DHA incorporated into PPLs compared to lean participants. Non-esterified plasma PUFA and oxylipid analysis showed ω-6 oxylipids were more abundant in the obese plasma pool. These ω-6 oxylipids are associated with increased angiogenesis (i.e. epoxyeicosatrienoates), reactive oxygen species (i.e. 9-hydroxyeicosatetraenoate), and inflammation resolution (i.e. Lipoxin A4). In summary, BMI is directly associated with specific PPL FA and increased ω-6 oxylipids.

BackgroundObesity increases the risk of colon cancer. It is also known that most colorectal cancers develop from adenomatous polyps. However, the effects of obesity and adipokines on colonic polyp formation are unknown.MethodsTo determine if BMI, waist circumference or adipokines are associated with colon polyps in males, 126 asymptomatic men (48–65 yr) were recruited at time of colonoscopy, and anthropometric measures as well as blood were collected. Odds ratios were determined using polytomous logistic regression for polyp number (0 or ≥3) and polyp type (no polyp, hyperplastic polyp, tubular adenoma).Results41% of the men in our study were obese (BMI ≥30). The odds of an obese individual having ≥3 polyps was 6.5 (CI: 1.3–33.0) times greater than those of a lean (BMI<25) individual. Additionally, relative to lean individuals, obese individuals were 7.8 (CI: 2.0–30.8) times more likely to have a tubular adenoma than no polyp. As BMI category increased, participants were 2.9 (CI: 1.5–5.4) times more likely to have a tubular adenoma than no polyps. Serum leptin, IP-10 and TNF-α were significantly associated with tubular adenoma presence. Serum leptin and IP-10 were significantly associated with increased likelihood of ≥3 polyps, and TNF-α showed a trend (p = 0.09).ConclusionsObese men are more likely to have at least three polyps and adenomas. This cross-sectional study provides evidence that colonoscopy should be recommended for obese, white males.

Diverticulosis can lead to diverticulitis, a colon condition involving inflammation and other complications. Diverticulosis can result from biological, behavioral, or genetic causes. However, the etiology of diverticulosis is unknown. Although diet is associated with diverticulosis, recent studies suggest other factors influence risk. We sought to identify anthropometric or serum markers that were associated with the presence of diverticulosis. To determine these associations, 126 asymptomatic men (48–65 yr) were recruited at the time of preventative screening colonoscopy. Anthropometric measures were taken, and blood was collected for serum protein analysis. Data were analyzed by logistic regression and factor analysis. Obese individuals (BMI >30) were 7.8 (CI: 2.3–26.3) times more likely than normal weight (BMI <25) individuals to have diverticulosis. The relationship was similar for waist circumference. Individuals with a waist circumference >45 inches were 8.1 (CI: 2.8–23.8) times more likely to have diverticulosis than those with a waist circumference <38 inches. Leptin was also positively associated with diverticulosis (OR = 5.5, CI: 2.0–14.7). Both low molecular weight adiponectin (LMW, OR = 0.50; CI: 0.3–0.8) and the soluble receptor for advanced glycation end products (sRAGE, OR = 0.4, CI: 0.3–0.7) were inversely related to the presence of diverticulosis. sRAGE levels were not correlated with leptin or C-peptide concentrations. The pattern of high BMI, waist circumference, leptin and C-peptide increased the odds of diverticulosis while the pattern of high levels of sRAGE and LMW adiponectin decreased the odds of diverticulosis. Associations between diverticulosis and anthropometric or serum markers may elucidate the origins of diverticulosis and may enable physicians to identify individuals at risk for diverticulitis.

Background Dysregulated insulin signaling is thought to contribute to cancer risk. Methods To determine if insulin-related serum factors are associated with colon polyps, 126 asymptomatic men (48–65yr) were recruited at colonoscopy. Blood was collected. Odds ratios were determined using polytomous logistic regression for polyp number and type. Results Males with serum C-peptide concentration >3.3 ng/ml were 3.8 times more likely to have an adenoma relative to no polyp than those with C-peptide ≤1.8 ng/ml. As C-peptide tertile increased, an individual was 2 times more likely to have an adenoma (p=0.01) than no polyp. There were no associations between insulin-like growth factor or its binding proteins with polyp number or type. Males with soluble receptor for advanced glycation end products (sRAGE) concentration >120.4 pg/ml were 0.25 times less likely to have ≥3 polyps relative to no polyps compared to males with sRAGE ≤94.5 pg/ml. For each increase in sRAGE tertile, a man was 0.5 times less likely to have ≥3 polyps than no polyps (p=0.03). Compared to males with a serum vascular endothelial growth factor (VEGF) concentration ≤104.7 pg/ml, males with a serum VEGF concentration >184.2 pg/ml were 3.4 times more likely to have ≥3 polyps relative to no polyps. As the VEGF tertile increased, a man was 1.9 times more likely to have ≥3 polyps than no polyps (p=0.049). Conclusions Serum concentrations of C-peptide, sRAGE, and VEGF may indicate which men could benefit most from colonoscopy. Impact Identification of biomarkers could reduce medical costs through the elimination of colonoscopies on low-risk individuals.

Chronic inflammation contributes to colorectal carcinogenesis. To determine if serum cytokines are associated with colon polyps, 126 asymptomatic men (48–65yr) were recruited at colonoscopy. Serum cytokine concentrations were measured. Odds ratios were determined using polytomous logistic regression for polyp number and type. Males with serum monocyte chemotactic protein-3 (MCP-3) or soluble interleukin-4 receptor (sIL-4R) concentrations in the highest tertile were 0.2 times less likely to have ≥3 polyps relative to no polyps. For each increase in serum MCP-3 or sIL-4R tertile a man was about 0.4 times less likely to have ≥3 polyps than no polyps. Males with serum concentrations of interferon-α2 (IFN-α2) or interleukin (IL)-7 in the highest tertile were 3 times more likely to have an adenoma relative to no polyps. Those with serum IL-8 concentrations in the highest tertile were 4 times more likely to have an adenoma relative to no polyps. For each increase in serum IFN-α2, IL-7 or IL-8 tertile an individual was 1.8 times more likely to have an adenoma than no polyp. Serum concentrations of MCP-3, sIL-4R, IFN-α2, IL-7 and IL-8 may indicate which men are more likely to have colorectal polyps.

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Obesity is known to increase the risk of colon cancer, and most colorectal cancers develop from adenomatous polyps. However, the effects of obesity on colonic polyp formation are unknown. The aim of this study was to determine if BMI was associated with advanced colon polyps in males. 126 men (48 – 65 yr) were recruited at time of first colonoscopy, and anthropometric measures were collected. Odds ratios were determined using logistic regression for polyp number (0 or ≥ 3) and polytomous logistic regression for polyp severity (no polyp, hyperplastic polyp, tubular adenoma). 41% of the men in our study were obese (BMI ≥ 30). Obese participants were 6.8 (CI: 1.4 – 34.6) times more likely than those who were lean (BMI < 25) to have ≥ 3 polyps than no polyps. For each category increase in BMI (lean, overweight, obese), an individual was 2.5 (CI: 1.2 – 5.4) times more likely to have ≥ 3 polyps than no polyps. Additionally, relative to lean individuals, obese individuals were 7.7 (CI: 2.0 – 29.7) times more likely to have a tubular adenoma then no polyp. As BMI category increased, participants were 2.8 (CI: 1.5 – 5.2) times more likely to have a tubular adenoma than no polyps. Due to the increased number and severity of polyps, earlier screening for polyps in obese individuals may be warranted.Grant Funding Source: NCI 1R03CA142000 and MSU CTSI

Activation of the insulin ‐‐ insulin‐like growth factor (IGF) signaling axis is hypothesized to increase colon cancer risk. The aim of this study was to determine if serum factors related to insulin or insulin signaling were associated with advanced colon polyps in males. 126 men (48 ‐ 65 yr) were recruited at time of colonoscopy, and blood was collected. Odds ratios were determined using logistic regression for polyp number and polytomous logistic regression for polyp severity. 29% of the men in our study had a tubular adenoma. Participants with C‐peptide levels above 3.3ng/ml were 3.8 (CI: 1.3 ‐ 11.1) times more likely than those with C‐peptide levels less than 1.8ng/ml to have a tubular adenoma. For each category increase in C‐peptide, an individual was 2.0 (CI: 1.2 ‐ 3.4) times more likely to have a tubular adenoma than no polyp. Those individuals with serum soluble receptor for advanced glycation end products (sRAGE) greater than 120.4pg/ml were 0.3 (CI: 0.1 ‐ 0.9) times less likely than those with sRAGE lower than 94.5pg/ml to have 蠅3 polyps than no polyps. For each category increase in sRAGE, an individual was 0.5 (CI: 0.3 ‐ 0.9) times less likely to have 蠅3 polyps than no polyps. Other factors, such as insulin growth factor binding proteins, were not associated with polyp presence or severity in this population. Serum C‐peptide levels are a potential biomarker of polyp severity in white males. Grant Funding Source: Supported by NCI 1R03CA142000 and MSU CTSI