The Association of Serum Total Peptide YY (PYY) with Obesity and Body Fat Measures in the CODING Study.

Background: PYY is an appetite suppressing hormone. Low circulating PYY has been linked to greater BMI. However data is controversial and this association has not been verified in large human populations.

Food addiction: its prevalence and significant association with obesity in the general population.

Background: 'Food addiction' shares a similar neurobiological and behavioral framework with substance addiction. However whether, and to what degree, 'food addiction' contributes to obesity in the general population is unknown.

Objectives: to assess 1) the prevalence of 'food addiction' in the Newfoundland population; 2) if clinical symptom counts of 'food addiction' were significantly correlated with the body composition measurements; 3) if food addicts were significantly more obese than controls, and 4) if macronutrient intakes are associated with 'food addiction'.

Short-term overfeeding increases circulating adiponectin independent of obesity status.

Background: Adiponectin is an adipose tissue derived hormone which strengthens insulin sensitivity. However, there is little data available regarding the influence of a positive energy challenge (PEC) on circulating adiponectin and the role of obesity status on this response.

Objective: The purpose of this study was to investigate how circulating adiponectin will respond to a short-term PEC and whether or not this response will differ among normal-weight(NW), overweight(OW) and obese(OB).

Circulating glucagon-like peptide-1 increases in response to short-term overfeeding in men.

Background: Glucagon-like Peptide-1 (GLP-1) is an incretin hormone secreted from the gastrointestinal tract that facilitates the glucose-dependent insulin response. Additionally, GLP-1 is thought to be involved in energy homeostasis. Currently little is known about GLP-1's responsiveness to an energy surplus, a fundamental cause of obesity and diabetes.

High dietary magnesium intake is associated with low insulin resistance in the Newfoundland population.

Background: Magnesium plays a role in glucose and insulin homeostasis and evidence suggests that magnesium intake is associated with insulin resistance (IR). However, data is inconsistent and most studies have not adequately controlled for critical confounding factors.

Objective: The study investigated the association between magnesium intake and IR in normal-weight (NW), overweight (OW) and obese (OB) along with pre- and post- menopausal women.

Role of the immune system in hypertension: modulation by dietary antioxidants.

Hypertension is a major health problem worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease, and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role.

Serum acylated ghrelin concentrations in response to short-term overfeeding in normal weight, overweight, and obese men.

Background: Ghrelin, an orexigenic gut hormone secreted primarily from the stomach, is involved in energy homeostasis. However, little data is available regarding its response to energy surplus and the development of human obesity.

Objective: The present study investigated the response of circulating acylated ghrelin to a 7-day positive energy challenge.

Serum acylated ghrelin is negatively correlated with the insulin resistance in the CODING study.

Objective: Ghrelin is a 28-amino acid orexigenic peptide synthesized mainly in the stomach. Acute administration of ghrelin has been found to decrease insulin secretion. However, little data is available regarding whether ghrelin contributes to the long-term regulation of insulin resistance at the population level.

Serum peptide YY in response to short-term overfeeding in young men.

Background: Peptide YY (PYY), a gut hormone that inhibits appetite, has been linked to the development of obesity.

Objective: This study investigated the nutritional regulation of PYY after 7 d of overfeeding (70% above normal energy requirements) in normal-weight, overweight, and obese men.

Design: Sixty-nine men (aged 19-29 y) participated in the study.

Risk factors preceding type 2 diabetes and cardiomyopathy.

Type 2 diabetes (T2DM) and its complications such as cardiomyopathy, contribute significantly to morbidity and mortality worldwide. Increased adoption of westernized diets and decreased physical activity are contributing to the obesity epidemic which, in turn, increases the risk for T2DM. Other risk factors for T2DM include insulin resistance, dyslipidemia, hypertension, metabolic syndrome, and a genetic predisposition.

Role of methylglyoxal in essential hypertension.

Altered glucose metabolism due to insulin resistance is a common feature of essential hypertension in humans and in animal models. Elevated endogenous aldehydes in genetic (spontaneously hypertensive rats) and acquired (fructose-induced hypertensive rats) models of essential hypertension may be due to increased production of the reactive aldehyde methylglyoxal, resulting from altered glucose metabolism. Excess methylglyoxal binds sulfhydryl groups of membrane proteins, altering calcium channels and increasing cytosolic free Ca(2+) and blood pressure.

Antihypertensive effects of dietary protein and its mechanism.

Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at increased risk of stroke, heart disease and kidney failure. Both genetic and lifestyle factors, particularly diet, have been attributed an important role in the development of hypertension.

Higher Dietary Protein Intake is Associated with Lower Body Fat in the Newfoundland Population.

Background: Increased protein proportions in the diet combined with energy restriction has been shown to enhance weight loss during dietary intervention. It is not known if the beneficial effect of dietary protein exists in the general population under normal living conditions without a negative energy balance.

Methods: A total of 1834 participants (n = 443 men, n = 1391 women) were recruited from the CODING study.

Fructose and moderately high dietary salt-induced hypertension: prevention by a combination of N-acetylcysteine and L-arginine.

Diets containing 8% salt or 4% fructose (FR) cause insulin resistance and increase tissue methylglyoxal and advanced glycation end products (AGEs), platelet cytosolic-free calcium, and systolic blood pressure (SBP) in rats. In WKY rats, we have shown that moderately high salt, 4% NaCl (MHS) alone in diet does not cause hypertension, and when given along with 4% FR it does not have an additive effect. N-acetylcysteine (NAC) or L-arginine (ARG), treatment alone does not prevent hypertension in this model.

The antihypertensive effect of cysteine.

Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at an increased risk for stroke, heart disease and kidney failure. Essential hypertension results from a combination of genetic and lifestyle factors.

Plasma advanced glycation endproduct, methylglyoxal-derived hydroimidazolone is elevated in young, complication-free patients with Type 1 diabetes.

Objectives: Elevated advanced glycation endproducts (AGEs) are implicated in diabetic complications. Methylglyoxal-derived hydroimidazolone (MG-H) is one of the most abundant AGEs in vivo. Our objective was to develop a time-saving, specific method to measure free MG-H in plasma and determine its levels in complication-free young individuals with Type 1 diabetes (T1DM).

Modulation of oxidative stress-induced changes in hypertension and atherosclerosis by antioxidants.

An imbalance between reactive oxygen species and antioxidant reserve, referred to as oxidative stress, results in the altered structure and function of proteins, lipids and DNA. Oxidative stress is associated with hypertension and atherosclerosis, but it is unknown whether it is a causative or resultant factor. The authors suggest that insulin resistance is the key element in the pathogenesis of these diseases, and leads to abnormal glucose and lipid metabolism with an increase in reactive aldehydes.

Effect of moderately high dietary salt and lipoic acid on blood pressure in Wistar-Kyoto rats.

Background: Approximately one-half of hypertensive individuals are salt sensitive, and animal models of human hypertension also exhibit increased blood pressure when exposed to high-salt diets. Salt sensitivity is associated with insulin resistance, which results in altered glucose metabolism, increasing aldehydes. Previously, the authors have shown that a high-salt diet (8% NaCl) caused an increase in blood pressure, tissue aldehyde conjugates and cytosolic free calcium, with resulting adverse renal vascular changes, in Wistar-Kyoto rats.

The antihypertensive effect of arginine.

Hypertension is a leading cause of morbidity and mortality worldwide. Individuals with hypertension are at increased risk of stroke, heart disease and kidney failure. Although the etiology of essential hypertension has a genetic component, lifestyle factors such as diet play an important role.

Serum retinol-binding protein 4 concentrations in response to short-term overfeeding in normal-weight, overweight, and obese men.

Background: Retinol-binding protein 4 (RBP4) is a novel adipokine that induces insulin resistance in mice. Studies in humans have shown a correlation between serum RBP4 and insulin resistance in obese subjects and in subjects with type 2 diabetes. Few data are available regarding the nutritional regulation of RBP4.

Role of advanced glycation end products in hypertension and atherosclerosis: therapeutic implications.

The vascular diseases, hypertension and atherosclerosis, affect millions of individuals worldwide, and account for a large number of deaths globally. A better understanding of the mechanism of these conditions will lead to more specific and effective therapies. Hypertension and atherosclerosis are both characterized by insulin resistance, and we suggest that this plays a major role in their etiology.

Fructose-induced hypertension in Wistar-Kyoto rats: interaction with moderately high dietary salt.

We investigated the effects of 4% fructose plus moderately high salt (MHS) (4% NaCl) treatment on tissue aldehyde conjugates, platelet cytosolic free calcium ([Ca2+]i), renal morphology, and systolic blood pressure (SBP) in Wistar-Kyoto rats, and whether these effects were reversible (R) after withdrawal of treatment. At age 7 weeks, rats were divided into 4 groups: NS group, given normal salt (NS) diet (0.7% NaCl) for 18 weeks; NS+F(R) group, NS diet and fructose in water for 14 weeks, then 4 weeks fructose withdrawal; MHS+F group, NS diet and fructose for 6 weeks, then MHS diet and fructose for 12 weeks; and MHS+F(R) group, NS diet and fructose for 6 weeks, then MHS diet and fructose for 8 weeks, then MHS and fructose withdrawal for 4 weeks.

Plasma methylglyoxal and glyoxal are elevated and related to early membrane alteration in young, complication-free patients with Type 1 diabetes.

The reactive aldehydes methylglyoxal and glyoxal, arise from enzymatic and non-enzymatic degradation of glucose, lipid and protein catabolism, and lipid peroxidation. In Type 1 diabetes mellitus (T1DM) where hyperglycemia, oxidative stress, and lipid peroxidation are common, these aldehydes may be elevated. These aldehydes form advanced glycation end products (AGEs) with proteins that are implicated in diabetic complications.

Beneficial effect of low ethanol intake on the cardiovascular system: possible biochemical mechanisms.

Low ethanol intake is known to have a beneficial effect on cardiovascular disease. In cardiovascular disease, insulin resistance leads to altered glucose and lipid metabolism resulting in an increased production of aldehydes, including methylglyoxal. Aldehydes react non-enzymatically with sulfhydryl and amino groups of proteins forming advanced glycation end products (AGEs), altering protein structure and function.

Plasma protein advanced glycation end products, carboxymethyl cysteine, and carboxyethyl cysteine, are elevated and related to nephropathy in patients with diabetes.

In Diabetes Mellitus (DM), glucose and the aldehydes glyoxal and methylglyoxal modify free amino groups of lysine and arginine of proteins forming advanced glycation end products (AGEs). Elevated levels of these AGEs are implicated in diabetic complications including nephropathy. Our objective was to measure carboxymethyl cysteine (CMC) and carboxyethyl cysteine (CEC), AGEs formed by modification of free cysteine sulfhydryl groups of proteins by these aldehydes, in plasma proteins of patients with diabetes, and investigate their association with the albumin creatinine ratio (ACR, urine albumin (mg)/creatinine (mmol)), an indicator of nephropathy.