Effect of vitamin D supplementation on cardiac-metabolic risk factors in elderly: a systematic review and meta-analysis of clinical trials.

BACKGROUND: There has been a longstanding interest in the potential effect of vitamin D in preventing cardiac-metabolic diseases. However, there are divergent results regarding the impact of vitamin D supplementation (VDS) on managing cardiac-metabolic outcomes in the elderly population. MATERIAL AND METHOD: We systematically searched electronic databases; Web of Science, PubMed, Scopus, EMBASE, Cochrane, and ProQuest. We included all trials that evaluated the effect of VDS on cardiac-metabolic risk factors in the elderly population, which were published until 30 September 2021. The effects of VDS on cardiac-metabolic outcomes were assessed using standardized mean difference (SMD). A random-effect model was used to pool the SMD and 95% confidence interval (CI). RESULT: The literature search identified 4409 studies, of which 12 trials met inclusion criteria. Results of random effect meta-analysis indicated a significant reduction in total cholesterol (TC) (SMD: - 0.14 mg/dl; 95% CI: - 0.25, - 0.02) and triglyceride (TG) (SMD: - 0.45 mg/dl; 95% CI: - 0.86, - 0.04) with VDS compared to the placebo. The subgroup analyses revealed that the reduction of TG in patients with diabetes and vitamin D deficiency was significant. Furthermore, short-term intervention (≤ 6 months) induced a significantly lower level of TG and insulin in comparison to longer duration (> 6 months). CONCLUSION: The study suggests that VDS could improve insulin concentration and dyslipidemia in the elderly population. The systematic review was registered in Alborz university of medical sciences with 2060-01-03-1397 number and the Ethics council IR.ABZUMS.REC.1397.207 number.

Food Insecurity and Dietary Intake Among Elderly Population: A Systematic Review.

BACKGROUND: This review seeks to determine the relationship between food insecurity among elderly people over the past decades and nutrient deficiency, which is rather unclear. We aim to systematically review the relationship between food insecurity and dietary intake among elderly population. METHODS: In this systematic review, we systematically searched the international databases including PubMed, Web of Sciences, and Scopus for scientifically related papers which have been published up until January 2018. For a more refined search, we used the Medical Subject Headings (MeSH) terms and Emtree. In terms of search protocol, no restrictions were placed on time and language. Two independent reviewers conducted the data refining processes. Validated form (PRISMA) was used to conduct quality assessment and data extraction. RESULTS: Eight cross sectional studies have been included in this review. Two of the studies were conducted in Asia and the remaining six studies were largely based in the United States and Canada. Food insecurity was associated with low levels of vitamin and mineral intakes such as vitamins E, A, B, and D and also zinc, calcium, magnesium, and iron. Most studies also reported insufficient energy, and micro and macronutrients intake among elderly people. CONCLUSIONS: The findings of this review evidence a considerable amount of food insecurity and nutrient deficiency, including vitamins E, C, D, B 2, and B 12 and zinc, phosphorus, and calcium among elderly population. These findings could be used as reliable evidence by policy makers and future complementary analyses.

Eficacia y seguridad de empagliflozina en combinación con otros hipoglucemiantes orales en pacientes con diabetes mellitus tipo 2 / Efficacy and safety of empagliflozin in combination with other oral hypoglycemic agents in patients with type 2 diabetes mellitus

Introducción: Analizar la eficacia y la seguridad de empagliflozina en combinación con otros hipoglucemiantes orales en pacientes con diabetes mellitus tipo 2. Métodos: Análisis de 3 ensayos fase III en pacientes con diabetes mellitus tipo 2 (n=1.801) que recibieron placebo, empagliflozina 10 o 25mg, una vez al día, durante 24 semanas, en combinación con metformina, metformina+sulfonilurea o pioglitazona±metformina. Resultados: Empagliflozina redujo significativamente la HbA1c (reducción media ajustada vs. placebo con empagliflozina 10 mg: -0,58% [IC 95%: -0,66; -0,49]; p < 0,0001 y con empagliflozina 25 mg -0,62% [IC 95%: -0,70; -0,53], p<0,0001), el peso (reducción media ajustada vs. placebo con empagliflozina 10 mg: -1,77kg [IC 95%: -2,05; -1,48]; p < 0,0001 y con empagliflozina 25 mg: -1,96 kg [IC 95%: -2,24; -1,67], p < 0,0001) y la presión arterial sistólica y diastólica. La frecuencia de efectos adversos fue del 64% con placebo, del 63,9% con empagliflozina 10 mg y del 60,9% con empagliflozina 25 mg. Las hipoglucemias confirmadas (menor o igual a 70 mg/dl y/o requiriendo asistencia) ocurrieron en un 3,9% de los pacientes con placebo, un 6,9% con empagliflozina 10 mg y un 5,3% con empagliflozina 25 mg. Las infecciones del tracto urinario acontecieron en un 9,4% con placebo, un 10,2% con empagliflozina 10 mg y un 8,3% con empagliflozina 25 mg. Las infecciones genitales se comunicaron en un 1,0% de los pacientes con placebo, un 4,6% con empagliflozina 10 mg y un 3,5% con empagliflozina 25 mg. Conclusiones: Empagliflozina en combinación con otros tratamientos orales vs. placebo disminuyó significativamente la HbA1c, el peso corporal y la presión arterial sistólica/diastólica, con un buen perfil de seguridad y tolerancia (AU)

Introduction: To analyze the efficacy and safety of empagliflozin combined with other oral hypoglycemic agents in patients with type 2 diabetes mellitus. Methods: Pooled analysis of three phase III trials in patients with type 2 diabetes mellitus (n=1,801) who received placebo or empagliflozin 10 or 25 mg once daily for 24 weeks, in combination with metformin, metformin+sulphonylurea or pioglitazone ± metformin. Results: Empagliflozin significantly decreased HbA1c (adjusted mean reduction vs placebo with empagliflozin 10mg: -0.58% [95% CI: -0.66; -0.49]; P<.0001, and with empagliflozin 25 mg: -0.62% [95% CI: -0.70; -0.53], P<.0001), weight (adjusted mean reduction vs placebo with empagliflozin 10 mg: -1.77 kg [95% CI: -2.05; -1.48]; P <.0001, and with empagliflozin 25mg: -1.96kg [95% CI: -2.24; -1.67], P<.0001), and systolic and diastolic blood pressure (SBP/DBP). Adverse effect rates were 64% with placebo, 63.9% with empagliflozin 10 mg, and 60.9% with empagliflozin 25 mg. Documented episodes of hypoglycemia (is less than or equal to 70 mg/dL and/or requiring care) occurred in 3.9% of patients with placebo, 6.9% of patients with empagliflozin 10 mg, and 5.3% of patients with empagliflozin 25 mg. Urinary tract infections developed in 9.4% of patients with placebo, 10.2% of patients with empagliflozin 10 mg, and 8.3% of patients with empagliflozin 25 mg. Genital infections were reported in 1.0% of patients with placebo, 4.6% of patients with empagliflozin 10mg, and 3.5% of patients with empagliflozin 25 mg. Conclusions: Empagliflozin combined with other oral treatments decreased HbA1c, body weight, and SBP/DBP as compared to placebo, with a good safety and tolerability profile (AU)

Efficacy and safety of empagliflozin in combination with other oral hypoglycemic agents in patients with type 2 diabetes mellitus. / Eficacia y seguridad de empagliflozina en combinación con otros hipoglucemiantes orales en pacientes con diabetes mellitus tipo 2.

INTRODUCTION: To analyze the efficacy and safety of empagliflozin combined with other oral hypoglycemic agents in patients with type 2 diabetes mellitus. METHODS: Pooled analysis of three phase III trials in patients with type 2 diabetes mellitus (n=1,801) who received placebo or empagliflozin 10 or 25mg once daily for 24 weeks, in combination with metformin, metformin+sulphonylurea or pioglitazone ± metformin. RESULTS: Empagliflozin significantly decreased HbA1c (adjusted mean reduction vs placebo with empagliflozin 10mg: -0.58% [95% CI: -0.66; -0.49]; P<.0001, and with empagliflozin 25mg: -0.62% [95% CI: -0.70; -0.53], P<.0001), weight (adjusted mean reduction vs placebo with empagliflozin 10mg: -1.77kg [95% CI: -2.05; -1.48]; P<.0001, and with empagliflozin 25mg: -1.96kg [95% CI: -2.24; -1.67], P<.0001), and systolic and diastolic blood pressure (SBP/DBP). Adverse effect rates were 64% with placebo, 63.9% with empagliflozin 10mg, and 60.9% with empagliflozin 25mg. Documented episodes of hypoglycemia (≤70mg/dL and/or requiring care) occurred in 3.9% of patients with placebo, 6.9% of patients with empagliflozin 10mg, and 5.3% of patients with empagliflozin 25mg. Urinary tract infections developed in 9.4% of patients with placebo, 10.2% of patients with empagliflozin 10mg, and 8.3% of patients with empagliflozin 25mg. Genital infections were reported in 1.0% of patients with placebo, 4.6% of patients with empagliflozin 10mg, and 3.5% of patients with empagliflozin 25mg. CONCLUSIONS: Empagliflozin combined with other oral treatments decreased HbA1c, body weight, and SBP/DBP as compared to placebo, with a good safety and tolerability profile.

Empagliflozin in combination with oral agents in young and overweight/obese Type 2 diabetes mellitus patients: A pooled analysis of three randomized trials.

AIMS: This analysis aimed to evaluate efficacy and safety of empagliflozin in combination therapy in <65 y.o. patients, overweight/obese, and with uncontrolled T2DM. METHODS: Pooled analysis from three phase-III trials, in <65 y.o. patients, with BMI 25-35kg/m2, and HbA1c ≥8% at baseline. Patients (N=439) were randomized to placebo (n=138), empagliflozin 10mg (n=160), or empagliflozin 25mg (n=141) once daily (24weeks) as add-on to metformin, to metformin plus sulfonylurea, or to pioglitazone ± metformin. RESULTS: At week 24, adjusted mean (SE) changes from baseline in HbA1c were -0.19% (0.07) for placebo vs. -1.10% (0.07) and -1.10% (0.07) for empagliflozin 10 and 25mg, respectively (both p<0.001). Adjusted mean (SE) changes from baseline in weight were -0.33kg (0.21) for placebo vs. -1.94kg (0.19) and -2.14kg (0.20) for empagliflozin 10 and 25mg, respectively (both p<0.001). Adverse events were reported in 57.2% on placebo, 64.4% on empagliflozin 10mg and 59.6% on empagliflozin 25mg. Genital infection AEs were reported in 1.4% on placebo, 3.8% on empagliflozin 10mg, and 5.0% on empagliflozin 25mg. CONCLUSIONS: In this specific population, empagliflozin in combination with other oral agents, significantly reduced HbA1c and body weight and was well tolerated.

Effect of diabetes on caregiver burden in an observational study of individuals with Alzheimer's disease.

BACKGROUND: The burden on caregivers of patients with Alzheimer's disease (AD) is associated with the patient's functional status and may also be influenced by chronic comorbid medical conditions, such as diabetes. This post-hoc exploratory analysis assessed whether comorbid diabetes in patients with AD affects caregiver burden, and whether caregivers with diabetes experience greater burden than caregivers without diabetes. Caregiver and patient healthcare resource use (HCRU) were also assessed. METHODS: Baseline data from the GERAS observational study of patients with AD and their caregivers (both n = 1495) in France, Germany and the UK were analyzed. Caregiver burden was assessed using the Zarit Burden Interview (ZBI). Caregiver time on activities of daily living (ADL: basic ADL; instrumental ADL, iADL) and supervision (hours/month), and caregiver and patient HCRU (outpatient visits, emergency room visits, nights hospitalized) were assessed using the Resource Utilization in Dementia instrument for the month before the baseline visit. Regression analyses were adjusted for relevant covariates. Time on supervision and basic ADL was analyzed using zero-inflated negative binomial regression. RESULTS: Caregivers of patients with diabetes (n = 188) were younger and more likely to be female (both p < 0.05), compared with caregivers of patients without diabetes (n = 1307). Analyses showed caregivers of patients with diabetes spent significantly more time on iADL (+16 %; p = 0.03; increases were also observed for basic ADL and total caregiver time but did not reach statistical significance) and had a trend towards increased ZBI score. Patients with diabetes had a 63 % increase in the odds of requiring supervision versus those without diabetes (p = 0.01). Caregiver and patient HCRU did not differ according to patient diabetes. Caregivers with diabetes (n = 127) did not differ from those without diabetes (n = 1367) regarding burden/time, but caregivers with diabetes had a 91 % increase in the odds of having outpatient visits (p = 0.01). CONCLUSIONS: This cross-sectional analysis found caregiver time on iADL and supervision was higher for caregivers of patients with AD and diabetes versus without diabetes, while HCRU was unaffected by patient diabetes. Longitudinal analyses assessing change in caregiver burden over time by patient diabetes status may help clarify the cumulative impact of diabetes and AD dementia on caregiver burden.

Sociodemographic and Clinical Predictors of Self-Management among People with Poorly Controlled Type 1 and Type 2 Diabetes: The Role of Illness Perceptions and Self-Efficacy.

Self-management is critical if people with diabetes are to minimise their risk of macrovascular and microvascular complications, yet adherence to self-management recommendations is suboptimal. Understanding the predictors of optimal diabetes self-management in specific populations is needed to inform effective interventions. This study investigated the role of demographic and clinical characteristics, illness perceptions, and self-efficacy in explaining adherence to self-management recommendations among people with poorly controlled diabetes in North West of England. Illness perceptions and self-efficacy data were collected using validated questionnaires and clinical data were obtained from hospital records. Correlations were used to investigate bivariate relationships between independent variables and self-management, and multiple regression techniques were used to determine demographic and psychosocial predictors of self-management. Various demographic and clinical characteristics were associated with adherence to self-management recommendations. In particular, employment status explained 11% of the variation in adherence to foot care whilst diabetes treatment category explained 9% of exercise and 21% of the variations in SMBG recommendations. Also, 22% and 8% of the variations in overall self-management were explained by illness perceptions and self-efficacy beliefs, respectively. Illness perceptions and self-efficacy beliefs of people with poorly controlled diabetes are important predictors of their self-management behaviours and could potentially guide effective interventions.

A combined continuous and interval aerobic training improves metabolic syndrome risk factors in men.

Individuals with metabolic syndrome have significantly higher risk of cardiovascular disease and type 2 diabetes leading to premature death mortality. Metabolic syndrome has a complex etiology; thus, it may require a combined and multi-targeted aerobic exercise regimen to improve risk factors associated with it. Therefore, the aim of this study was to evaluate the effect of combined continuous and interval aerobic training on patients with metabolic syndrome. Thirty adult male with metabolic syndrome (54±8 years) were randomly divided into two groups: test training group (TTG; n=15) and control group (CG; n=15). Subjects in TTG performed combined continuous and interval aerobic training using a motorized treadmill three times per week for 16 weeks. Subjects in CG were advised to continue with their normal activities of life. Twenty-two men completed the study (eleven men in each group). At the end of the study, in TTG, there were significant (for all, P<0.05) reductions in total body weight (-3.2%), waist circumference (-3.43 cm), blood pressure (up to -12.7 mmHg), and plasma insulin, glucose, and triacylglyceride levels. Moreover, there were significant (for all, P<0.05) increases VO2max (-15.3%) and isometric strength of thigh muscle (28.1%) and high-density lipoprotein in TTG. None of the above indices were changed in CG at the end of 16-week study period. Our study suggests that adoption of a 16-week combined continuous and interval aerobic training regimen in men with metabolic syndrome could significantly reduce cardiovascular risk factors in these patients.

Omega-3 fatty acid supplementation and cognitive function: are smaller dosages more beneficial?

As longevity increases, so does the global prevalence of cognitive dysfunction. Numerous lifestyle and/or dietary interventions such as omega-3 fatty acids have been suggested to improve memory. Therefore, this study examined the consistency and strength of the impact of supplementation of omega-3 fatty acids on overall cognitive function using systematic reviews and meta-analytic methods. Of 905 studies retrieved from all searches, 12 randomized controlled trials were included in the meta-analysis. There were differences between studies reporting outcomes for single memory function parameters. Subgroup analysis of doses used (low versus high) indicated that subjects receiving low (<1.73 g/day) doses of omega-3 fatty acids had a significant reduction in cognitive decline rate (-0.07, 95% confidence interval -0.01, -0.02) but there was no evidence for beneficial effects at higher doses (+0.04, 95% confidence interval -0.06, +0.14) compared with the placebo group. This study suggests that omega-3 fatty acids may be beneficial in preventing memory decline at lower doses.

Ethnic differences and socio-demographic predictors of illness perceptions, self-management, and metabolic control of type 2 diabetes.

OBJECTIVES: This study investigated ethnic differences in diabetes-specific knowledge, illness perceptions, self-management, and metabolic control among black-African, black-Caribbean,and white-British populations with type 2 diabetes. The study also examined associations between demographic/disease characteristics and diabetes-specific knowledge, illness perceptions, self-management, and metabolic control in each of the three ethnic groups. DESIGN: Cross-sectional. SETTING: Diabetes/retinal screening clinics in Hackney and Brent, London. METHODS: Black-African, black-Caribbean and white-British populations with type 2 diabetes were asked to participate. Questionnaires measuring demographic/disease characteristics, diabetes-specific knowledge, self-management, and illness perceptions were used for data collection. Data for glycated hemoglobin (HbA1c) and microvascular complications were obtained from medical records. Ethnic differences in diabetes-related measures were estimated using analysis of variance/covariance. Multiple regression techniques were used to determine relationships between demographic/disease characteristics and measured diabetes-related outcomes. RESULTS: Three hundred and fifty-nine patients participated in the study. White-British participants had high diabetes-specific knowledge compared to their black-African and black-Caribbean counterparts. Black-Africans reported better adherence to self-management recommendations than the other ethnic groups. Compared to the white-British patients, black-African and black-Caribbean participants perceived diabetes as a benign condition that could be cured. Educational status and treatment category were determinants of diabetes-specific knowledge in all three ethnic groups. However, different demographic/disease characteristics predicted adherence to self-management recommendations in each ethnic group. CONCLUSION: Clearly, there is disease (diabetes) knowledge-perception variation between different ethnic groups in the UK which may partly influence overall disease outcome. It is plausible to recommend screening, identifying, and dispelling misconceptions about diabetes among ethnic minority patients by health care professionals as well as emphasizing the importance of self-management in managing chronic diseases such as diabetes.

Short-Term Therapy with Rosiglitazone, a PPAR-γ Agonist, Improves Metabolic Profile and Vascular Function in Nonobese Lean Wistar Rats.

A number of preclinical and clinical studies have reported blood-pressure-lowering benefits of thiazolidinediones in diabetic subjects and animal models of diabetes. This study was designed to further elucidate vascular effects of rosiglitazone, on healthy nonobese, lean animals. Adult male Wistar rats were randomized and assigned to control and rosiglitazone-treated groups and were dosed daily with either vehicle or rosiglitazone (10 mg kg(-1) day(-1)) by oral gavage for 5 days. Compared with control group, rosiglitazone treatment significantly reduced plasma levels of triglycerides (>240%) and nonesterified free fatty acids (>268%) (both, P < 0.001). There were no changes in vascular contractility to KCl or noradrenaline between two groups. However, rosiglitazone therapy improved carbamylcholine-induced vasorelaxation (93 ± 3 % versus control 78 ± 2, P < 0.01) an effect which was abolished by L-NAME. There was no difference in sodium nitroprusside-induced vasorelaxation between the control and rosiglitazone-treated animals. These results indicate that short-term rosiglitazone therapy improves both metabolic profile and vascular function in lean rats. The vascular effect of rosiglitazone appears to be mediated by alteration in NO production possibly by activation of endothelial PPARγ. This increased NO production together with improved lipid profile may explain mechanism(s) of blood-pressure-lowering effects of thiazolidinediones on both human and experimental animals.

Effects of diet-induced obesity on protein expression in insulin signaling pathways of skeletal muscle in male Wistar rats.

BACKGROUND: The prevalence of diet-induced obesity is increasing globally, and posing significant health problems for millions of people worldwide. Diet-induced obesity is a major contributor to the global pandemic of type 2 diabetes mellitus. The reduced ability of muscle tissue to regulate glucose homeostasis plays a major role in the development and prognosis of type 2 diabetes. In this study, an animal model of diet-induced obesity was used to elucidate changes in skeletal muscle insulin signaling in obesity-induced diabetes. METHODS: Adult male Wistar rats were randomized and assigned to either a control group or to a test group. Controls were fed a standard laboratory pellet diet (chow-fed), while the test group had free access to a highly palatable diet (diet-fed). After 8 weeks, the diet-fed animals were subdivided into three subgroups and their diets were altered as follows: diet-to-chow, diet-fed with addition of fenofibrate given by oral gavage for a further 7 weeks, or diet-fed with vehicle given by oral gavage for a further 7 weeks, respectively. RESULTS: Untreated diet-fed animals had a significantly higher body weight and metabolic profile than the control chow-fed animals. Intramuscular triacylglyceride levels in the untreated obese animals were significantly higher than those in the control chow-fed group. Expression of protein kinase C beta, phosphatidylinositol 3, Shc, insulin receptor substrate 1, ERK1/2, and endothelial nitric oxide synthase was significantly increased by dietary obesity, while that of insulin receptor beta, insulin receptor substrate 1, and protein kinase B (Akt) were not affected by obesity. CONCLUSION: These data suggest that diet-induced obesity affects insulin signaling mechanisms, leading to insulin resistance in muscle.

The effects of diet-induced obesity on hepatocyte insulin signaling pathways and induction of non-alcoholic liver damage.

The prevalence of diet-induced obesity is increasing amongst adults and children worldwide, predisposing millions of people to an array of health problems that include metabolic syndrome, non-alcoholic fatty liver disease and non-alcoholic steatohepatitis. In this study we used experimental animals to investigate the effects of dietary obesity on markers of hepatic insulin signaling as well as structural changes in hepatocytes. Adult male Wistar rats were randomized and assigned to either a control group or a test group. Controls were fed standard laboratory pelleted diet (chow-fed), while the test group had free access to a highly-palatable diet (HPD). After eight weeks, the HPD-fed animals were subdivided into three subgroups and their diets altered as follows: HPD-to-chow, HPD with the addition of fenofibrate given by oral gavage for a further seven weeks, or HPD with vehicle (1% carboxymethylcellulose at 1 mL/kg body weight) given by oral gavage for a further seven weeks, respectively. Untreated diet-fed animals had significantly higher body weight, liver weight, and all measured metabolic profiles compared with chow-fed and treated diet-fed groups. Expression of kinases IRß, IRS-1, AKt, eNOS, Shc and ERK1/2 were unaffected by obesity, while IRS-2 and P I3 kinase levels were significantly reduced in untreated HPD animals. Compared with chow-fed animals, steatosis and steatohepatitis were almost doubled in animals from untreated HPD, while removal of HPD and fenofibrate-treatment reduced steatosis by 40% and 80% respectively. These data suggest that diet-induced obesity affects intracellular insulin signaling mechanisms, namely IRS-2 and PI 3-kinase, leading to hepatic insulin resistance. Moreover, diet-induced obesity induces fatty liver, an effect which can be reversed by either removal of the source of obesity or treatment with fenofibrate, a peroxisome proliferator-activated receptor alpha agonist.

Review: omega-3 and memory function: to eat or not to eat.

At present it is estimated that 25% of the population older than 85 years have significant cognitive impairment. The global prevalence of cognitive impairment and dementia including Alzheimer's disease is expected to rise significantly in proportion to increased life expectancy. Deterioration of memory function and ultimately establishment of Alzheimer's disease (AD) severely debilitates the affected individual, uncompromisingly decreasing the quality of life of both affected patients and their care givers. Moreover, the cost of providing adequate care to patients with AD is a significant burden to both family and the health care providers. Therefore, various attempts have been made to identify means of either delaying the onset of cognitive impairment or improving memory function in patients affected by AD. Among a number of participants, importance of dietary fatty acids in particular omega-3 based fatty acids have gained significant momentum. This article aims to review published evidences for the role of omega-3 in memory function.

Obesity and Alzheimer's disease: a link between body weight and cognitive function in old age.

Obesity is now a global health hazard. It not only predisposes to an array of risk factors leading to increased morbidity and mortality amongst adults but it also has a major negative impact on children's health. The deleterious effects of obesity on cardiovascular system have now been well acknowledged. It causes insulin resistance that in turn leads to diabetes, hypertension and cardiovascular abnormalities. The vascular effects of obesity may have a role in the development of a rapidly growing disease of late life, Alzheimer's disease. The precise mechanisms of the association between adiposity and impairment of cognitive performance remain to be elucidated. However, negative impact of obesity on cognitive function may be, at least in part, due to vascular defects, impaired insulin metabolism and signaling pathway or a defect in glucose transport mechanisms in brain. This review examines the available data regarding the impact of obesity on cognitive function.

Obesity and cardiovascular dysfunction: A role for resveratrol?

SUMMARY: Obesity, characterized by excess adipose tissue is now becoming a worldwide epidemic. Various studies have suggested that obesity per se is an independent cardiovascular risk factor, as well as predisposing to type 2 diabetes, hypertension and dyslipidaemia. Furthermore, obesity induces insulin resistance, which is associated with development of cardiovascular diseases that include hypertension, and reduced endothelial function. A variety of pharmacological and physiological as well as surgical interventions have been used to counteract deleterious effects of obesity with some degree of success. A number of new medicinal agents are being considered as a candidate for managing obesity and its associated cardiovascular abnormalities. Resveratrol, a naturally occurring phenolic trihydroxystilbene substance, which is present in a variety of plants have been shown to reverse detrimental effects of diet-induced obesity. This review examines role of resveratrol as a future anti-obesity agent.:

The effects of physiological and pharmacological weight loss on adiponectin and leptin mRNA levels in the rat epididymal adipose tissue.

In subjects with obesity, diabetes and coronary artery disease, circulating levels of leptin increased while that of adiponectin is decreased. In this study we have investigated effects of physiological and pharmacological weight reduction on leptin and adiponectin mRNA expression. Wistar rats were fed either standard laboratory chow for 16 weeks (chow-fed) or given a fat-enriched, glucose-enriched diet (diet-fed) for 8 weeks. After 8 weeks, diet-fed group was subdivided into three subgroups, namely, an untreated obese, or were returned to chow diet, or treated with fenofibrate for further 8 week. After 16 weeks, compared with chow-fed group, diet-fed rats had significantly higher body weight, epididymal fat pad mass, and plasma levels of insulin, leptin, adiponectin, non-esterified fatty acids and triglycerides (P<0.001, for all). Moreover, untreated obese rats had significantly (P<0.01, for both) raised levels of Ob mRNA but reduced adiponectin mRNA levels in epididymal fat pads compared with chow-fed group. These changes were corrected by chronic removal of the high-energy diet and fenofibrate treatment. These findings indicate that physiological or pharmacological lowering of body weight together with circulating plasma lipids play a significant role in leptin and adiponectin synthesis and metabolism.

Differential vascular dysfunction in response to diets of differing macronutrient composition: a phenomenonological study.

BACKGROUND: Vascular dysfunction can develop from consumption of an energy-rich diet, even prior to the onset of obesity. However, the roles played by different dietary components remain uncertain. While attempting to develop models of obesity in a separate study, we observed that two high-energy diets of differing macronutrient compositions affected vascular function differently in overweight rats. METHODS: Male Wistar rats (n = 6/group) were fed diets providing varying percentages of energy from fat and carbohydrate (CHO). For 10 weeks, they were fed either chow, as control diet (10% of energy from fat; 63% from CHO), chow supplemented with chocolate biscuit (30% fat; 56% CHO) or a high-fat diet (45% fat; 35% CHO). Blood concentrations of biochemical markers of obesity were measured, and epididymal fat pads weighed as a measure of adiposity. Mesenteric arteries were dissected and their contractile and relaxant properties analysed myographically. Data were tested by analysis of variance (ANOVA). RESULTS: Weight gain and plasma concentrations of glucose, insulin and leptin were similar in all groups. However, biscuit-fed animals showed increased food intake (+27%; p < 0.01) and elevated concentrations of TGs and NEFAs (+41% and +17%; both p < 0.05). High-fat-fed animals showed an increase only in NEFAs (+38%; p < 0.01). Arterial vasoconstriction in response to NA and KCl increased only in biscuit-fed rats (both p < 0.01), while vasorelaxation in response to CCh and SNP, but not histamine, was attenuated in both groups (both p < 0.01). Furthermore, whereas the effect of the high-fat diet was most pronounced in endothelium-dependent vasorelaxation, the biscuit diet had the greater effect on endothelium-independent vasorelaxation. CONCLUSION: Vascular dysfunction resulting from consumption of a high-fat or combined relatively high-fat/high-CHO diet occurs through different physiological processes, which may be attributable to their differing macronutrient compositions. Combining potentially atherogenic macronutrients induces more extensive vascular impairment than that of high-fat alone, and may be attributable to the more marked dyslipidaemia observed with such a diet. Thus, these findings help clarify the role of dietary components in vascular impairment, which has implications for clinical approaches to preventing cardiovascular disease.

The effects of fenofibrate on metabolic and vascular changes induced by chocolate-supplemented diet in the rat.

Current evidences suggest that diet per se plays an important role in genesis of metabolic and vascular function abnormalities. We have investigated the effects of addition of a high-fat diet (chocolate) in the presence or absence of short-term (7 days) administration of fenofibrate on metabolic and vascular changes in adult male Wistar rats. Despite similarities in total body weight in all groups, compared with control fed groups, chocolate-supplemented animals had significantly higher plasma triacylglyceride and non-esterified fatty acids and leptin (for all, P<0.01), but not glucose or insulin levels. Fenofibrate treatment corrected metabolic changes. In the mesenteric arteries, responses to KCl and noradrenaline were significantly (for both, P<0.01) higher in chocolate-supplemented group. Furthermore, vasorelaxant responses to carbamylcholine, but not to sodium nitroprusside, were significantly (P<0.01) reduced in the chocolate-supplemented group. Although fenofibrate failed to improve noradrenaline and KCl responses, it was effective in improving carbamylcholine-induced vasorelaxation. These data suggest that high-fat diet has a profound effect on plasma lipid profile and vascular function. Furthermore, fenofibrate treatment may ameliorate high-fat diet effects on vascular function and metabolic changes.

Fenofibrate lowers adiposity and corrects metabolic abnormalities, but only partially restores endothelial function in dietary obese rats.

In humans, dietary-induced obesity markedly increases plasma lipid profile and impairs vascular function leading to increased incidence of cardiovascular events. We have recently reported that chronic withdrawal of obesity-inducing diet attenuates obesity and completely corrects endothelial function. The aim of this study was to investigate whether fenofibrate-induced decrease in adiposity would also correct vascular function in the presence of obesity-inducing diet. Wistar rats were fed with either standard laboratory chow (lean, n = 9) or given a highly palatable diet (diet-fed, n = 18) for 15 weeks. After 7 weeks, half of the diet-fed group was treated with fenofibrate (fenofibrate-treated, n = 9) for 8 weeks before being sacrificed. Untreated diet-fed (n = 9) rats had significantly higher body weight, total fat mass (by up to two-fold, p < 0.001 for both), and raised fasting plasma levels of insulin, leptin and triglycerides (up to 110%; p < 0.001), but not glucose or nonesterified fatty acids (NEFA) than both lean control and fenofibrate-treated groups. Resistance mesenteric arteries responses to KCl- and noradrenaline-induced vasoconstriction were similar in all three groups. However, compared with lean controls, endothelium-dependent vasorelaxation responses were shifted to the right in both untreated and fenofibrate-treated diet-fed groups. Fenofibrate treatment improved endothelium-dependent vasorelaxation at only high carbamycholine concentrations (10 microM). There were no differences in endothelium-independent vasorelaxation between the three groups. These results indicate that, in the presence of obesity-inducing diet, fenofibrate markedly reverses obesity and corrects insulin resistance and lipid profile, but it only has a limited beneficial effect on vascular function. Therefore, it seems that diet component rather than obesity per se plays a key role in the genesis of vascular abnormalities.