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1.
Braz J Med Biol Res ; 54(8): e10679, 2021.
Article in English | MEDLINE | ID: mdl-34037091

ABSTRACT

In spite of the many studies examining alcohol consumption, recent reviews have indicated that binge drinking has not been extensively studied. Furthermore, it is becoming increasingly clear that sleep is associated with many physiological functions and to drug addictions. The present study aimed to evaluate the relationship between alcohol binge drinking and insomnia in college students of health sciences. All first-year health sciences students (n=286) were evaluated in a cross-sectional study. Envelopes containing the Insomnia Severity Index (ISI), the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), and questions capturing sociodemographic data were distributed and collected in classes. It was found that most non-drinkers were female (70.6%), although there were no sex-related differences in the number of binge drinkers (more than 5 drinks on each occasion at least once a week), allowing statistical comparison. The Mann-Whitney U test indicated that the ISI scores were significantly greater in female than male binge drinkers (P=0.014). Moderate or severe insomnia was reported by 23% of the sample, with alcohol being the most frequently associated substance. A specialized intervention was suggested by ASSIST: brief for marijuana (19.2%) and tobacco (23.3%) use, and moderate (31.5%) or intensive (1.4%) for alcohol consumers. The data highlighted the need to pay attention to the habits of college students beyond obtaining scientific information. New data suggesting the influence of genetics on insomnia may be of importance when performing additional studies on the sex differences in alcohol binge drinking.


Subject(s)
Binge Drinking , Sleep Initiation and Maintenance Disorders , Alcohol Drinking/epidemiology , Binge Drinking/epidemiology , Brazil/epidemiology , Cross-Sectional Studies , Female , Humans , Male , Sleep Initiation and Maintenance Disorders/epidemiology , Students , Universities
2.
Braz. j. med. biol. res ; 54(8): e10679, 2021. tab
Article in English | LILACS | ID: biblio-1249325

ABSTRACT

In spite of the many studies examining alcohol consumption, recent reviews have indicated that binge drinking has not been extensively studied. Furthermore, it is becoming increasingly clear that sleep is associated with many physiological functions and to drug addictions. The present study aimed to evaluate the relationship between alcohol binge drinking and insomnia in college students of health sciences. All first-year health sciences students (n=286) were evaluated in a cross-sectional study. Envelopes containing the Insomnia Severity Index (ISI), the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), and questions capturing sociodemographic data were distributed and collected in classes. It was found that most non-drinkers were female (70.6%), although there were no sex-related differences in the number of binge drinkers (more than 5 drinks on each occasion at least once a week), allowing statistical comparison. The Mann-Whitney U test indicated that the ISI scores were significantly greater in female than male binge drinkers (P=0.014). Moderate or severe insomnia was reported by 23% of the sample, with alcohol being the most frequently associated substance. A specialized intervention was suggested by ASSIST: brief for marijuana (19.2%) and tobacco (23.3%) use, and moderate (31.5%) or intensive (1.4%) for alcohol consumers. The data highlighted the need to pay attention to the habits of college students beyond obtaining scientific information. New data suggesting the influence of genetics on insomnia may be of importance when performing additional studies on the sex differences in alcohol binge drinking.


Subject(s)
Humans , Male , Female , Binge Drinking/epidemiology , Sleep Initiation and Maintenance Disorders/epidemiology , Students , Universities , Brazil/epidemiology , Alcohol Drinking/epidemiology , Cross-Sectional Studies
3.
J Diabetes Complications ; 34(9): 107671, 2020 09.
Article in English | MEDLINE | ID: mdl-32651031

ABSTRACT

The COVID-19 pandemic has added an enormous toll to the existing challenge of diabetes care world-wide. A large proportion of patients with COVID-19 requiring hospitalization and/or succumbing to the disease have had diabetes and other chronic conditions as underlying risk factors. In particular, individuals belonging to racial/ethnic minorities in the U.S. and other countries have been significantly and disproportionately impacted. Multiple and complex socioeconomic factors have long played a role in increasing the risk for diabetes and now for COVID-19. Since the pandemic began, the global healthcare community has accumulated invaluable clinical experience on providing diabetes care in the setting of COVID-19. In addition, understanding of the pathophysiological mechanisms that link these two diseases is being developed. The current clinical management of diabetes is a work in progress, requiring a shift in patient-provider interaction beyond the walls of clinics and hospitals: the use of tele-medicine when feasible, innovative patient education programs, strategies to ensure medication and glucose testing availability and affordability, as well as numerous ideas on how to improve meal plans and physical activity. Notably, this worldwide experience offers us the possibility to not only prepare better for future disasters but also transform diabetes care beyond the COVID-19 era.


Subject(s)
Betacoronavirus , Coronavirus Infections/complications , Coronavirus Infections/epidemiology , Diabetes Mellitus/epidemiology , Diabetes Mellitus/therapy , Pneumonia, Viral/complications , Pneumonia, Viral/epidemiology , COVID-19 , Coronavirus Infections/therapy , Diabetes Mellitus/virology , Humans , Pandemics , Pneumonia, Viral/therapy , SARS-CoV-2
4.
Diabetes Obes Metab ; 16(3): 223-30, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23909985

ABSTRACT

AIM: To evaluate the efficacy and safety of initial combination therapy of sitagliptin 100 mg/day coadministered with all marketed doses of pioglitazone in patients with type 2 diabetes. METHODS: Patients with A1c ≥7.5 and ≤11.0% were randomized among seven arms that received, once daily, 100 mg sitagliptin alone; 15, 30 or 45 mg pioglitazone alone, or 100 mg sitagliptin plus 15, 30 or 45 mg pioglitazone for 54 weeks. The primary endpoint was change from baseline in A1c at week 24. Protocol-specified analyses compared combination therapies with monotherapies at respective dose-strengths and combination of sitagliptin plus pioglitazone 30 mg with pioglitazone 45 mg monotherapy. Post-hoc analyses compared sitagliptin plus pioglitazone 15 mg with pioglitazone monotherapy at the two higher doses. RESULTS: Initial combination therapy with sitagliptin and pioglitazone provided significantly greater reductions in A1c (0.4-0.7% differences) and other glycaemic endpoints than either monotherapy at the same doses. Combining sitagliptin with low-dose pioglitazone generally produced greater glycaemic improvements than higher doses of pioglitazone monotherapy (0.3-0.4% differences in A1c). Combination therapy was generally well tolerated; adverse events (AEs) of hypoglycaemia were reported with similar incidence (7.8-11.1%) in all treatment groups over the 54 weeks of study; oedema was reported in 0.5% of patients in the sitagliptin monotherapy group and 2.7-5.3% among pioglitazone-treated groups. Significant weight gain was observed in all combination-treated groups compared with the sitagliptin monotherapy group. CONCLUSIONS: Initial combination therapy with sitagliptin and pioglitazone provided better glycaemic control than either monotherapy and was generally well tolerated.


Subject(s)
Blood Glucose/drug effects , Diabetes Mellitus, Type 2/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/administration & dosage , Glycated Hemoglobin/drug effects , Hypoglycemic Agents/administration & dosage , Pyrazines/administration & dosage , Thiazolidinediones/administration & dosage , Triazoles/administration & dosage , Adolescent , Adult , Aged , Blood Glucose/metabolism , Double-Blind Method , Drug Administration Schedule , Drug Therapy, Combination , Female , Glycated Hemoglobin/metabolism , Humans , Hypoglycemia/drug therapy , Male , Middle Aged , Pioglitazone , Sitagliptin Phosphate , Treatment Outcome
5.
Braz J Med Biol Res ; 46(12): 1033-1039, 2013 12.
Article in English | MEDLINE | ID: mdl-24345912

ABSTRACT

The objective of this research was to evaluate the interference of ethanol consumption by female rats with cytokines involved in the sepsis process and its correlation with mortality, the main outcome of sepsis. Female Wistar rats in estrus phase were evaluated in three experiments. Experiment 1 (n=40) was performed to determine survival rates. Experiment 2 (n=69) was designed for biochemical analysis, measurement of cytokine and estrogen levels before and after sepsis, and experiment 3 (n=10) was performed to evaluate bacterial growth by colony counts of peritoneal fluid. In all experiments, treated animals were exposed to a 10% ethanol/water solution (v/v) as the single drinking source, while untreated animals were given tap water. After 4 weeks, sepsis was induced in the rats by ip injection of feces. In experiment 1, mortality in ethanol-exposed animals was delayed compared with those that drank water (48 h; P=0.0001). Experiment 2 showed increased tumor necrosis factor alpha (TNF-α) and decreased interleukin-6 (IL-6) and macrophage migration inhibitory factor in septic animals exposed to ethanol compared to septic animals not exposed. Sepsis also increased TNF-α and IL-6 levels in both ethanol- and water-exposed groups. Biochemical analysis showed higher creatinine, alanine aminotransferase and aspartate aminotransferase and decreased glucose levels in septic animals that were exposed to ethanol. In experiment 3, septic animals exposed to ethanol showed decreased numbers of colony-forming units than septic animals exposed to water. These results suggest that ethanol consumption delays the mortality of female rats in estrus phase after sepsis induction. Female characteristics, most probably sex hormones, may be involved in cytokine expression.

6.
Braz. j. med. biol. res ; 46(12): 1033-1039, dez. 2013. graf
Article in English | LILACS | ID: lil-695981

ABSTRACT

The objective of this research was to evaluate the interference of ethanol consumption by female rats with cytokines involved in the sepsis process and its correlation with mortality, the main outcome of sepsis. Female Wistar rats in estrus phase were evaluated in three experiments. Experiment 1 (n=40) was performed to determine survival rates. Experiment 2 (n=69) was designed for biochemical analysis, measurement of cytokine and estrogen levels before and after sepsis, and experiment 3 (n=10) was performed to evaluate bacterial growth by colony counts of peritoneal fluid. In all experiments, treated animals were exposed to a 10% ethanol/water solution (v/v) as the single drinking source, while untreated animals were given tap water. After 4 weeks, sepsis was induced in the rats by ip injection of feces. In experiment 1, mortality in ethanol-exposed animals was delayed compared with those that drank water (48 h; P=0.0001). Experiment 2 showed increased tumor necrosis factor alpha (TNF-α) and decreased interleukin-6 (IL-6) and macrophage migration inhibitory factor in septic animals exposed to ethanol compared to septic animals not exposed. Sepsis also increased TNF-α and IL-6 levels in both ethanol- and water-exposed groups. Biochemical analysis showed higher creatinine, alanine aminotransferase and aspartate aminotransferase and decreased glucose levels in septic animals that were exposed to ethanol. In experiment 3, septic animals exposed to ethanol showed decreased numbers of colony-forming units than septic animals exposed to water. These results suggest that ethanol consumption delays the mortality of female rats in estrus phase after sepsis induction. Female characteristics, most probably sex hormones, may be involved in cytokine expression.

7.
Diabetes Obes Metab ; 15(5): 403-9, 2013 May.
Article in English | MEDLINE | ID: mdl-23163880

ABSTRACT

AIMS: Ipragliflozin is a novel, selective inhibitor of sodium glucose co-transporter 2 (SGLT2 inhibitor) in clinical development for type 2 diabetes mellitus (T2DM) treatment. This study assessed the efficacy and safety of different doses of ipragliflozin. METHODS: In a 12-week, multicentre, double-blind, randomized, placebo-controlled, dose-finding study patients with inadequate glycaemic control on metformin monotherapy (≥1500 mg/day) were randomized to one of four ipragliflozin treatment groups (12.5, 50, 150 or 300 mg once daily) or placebo. Primary efficacy outcome was mean change from baseline in haemoglobin A1c (HbA1c) compared to placebo at week 12. Adverse events (AEs), vital signs and laboratory safety measurements were assessed. RESULTS: Ipragliflozin dose dependently decreased HbA1c from baseline to week 12 compared to placebo (-0.22, -0.34, -0.40 and -0.48% for ipragliflozin 12.5, 50, 150 and 300 mg, respectively). Decreases in body weight and blood pressure were observed for all ipragliflozin groups. AEs occurred in 39.7-51.4% of the ipragliflozin groups and 39.4% of placebo patients. Urinary tract infections (1.4-6.9 vs. 6.1%), genital infections (0-4.3 vs. 1.5%) and hypoglycaemia (0-5.9 vs. 3.0%) were similar in the ipragliflozin and placebo groups, respectively, without dose dependency. There were no clinically relevant effects on other safety measurements. CONCLUSIONS: Ipragliflozin treatment improved glycaemic control when added to metformin therapy and may be associated with weight loss and reductions in blood pressure compared to placebo. No safety or tolerability concerns were identified at any of the tested doses supporting the further development of ipragliflozin at ≥50 mg doses in T2DM patients.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Glucosides/administration & dosage , Glycated Hemoglobin/metabolism , Hypoglycemic Agents/administration & dosage , Metformin/administration & dosage , Thiophenes/administration & dosage , Biomarkers/blood , Diabetes Mellitus, Type 2/epidemiology , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Drug Therapy, Combination , Europe/epidemiology , Female , Humans , Male , Middle Aged , Time Factors , Treatment Outcome , United States/epidemiology
8.
Alcohol Alcohol ; 47(6): 677-82, 2012.
Article in English | MEDLINE | ID: mdl-22805349

ABSTRACT

AIMS: To evaluate the effects of chronic ethanol consumption on the development and the pathophysiology of sepsis, using an experimental model of polymicrobial peritonitis by feces i.p. injection. METHODS: Forty-day-old male Wistar rats were divided into groups for two experiments: A and B. Experiment A was performed for determination of mortality rates, while experiment B was designed for biochemical analysis and measurement of cytokines before and after sepsis. In both the experiments, treated animals were exposed to a 10% ethanol solution as the single drinking source for 4 weeks, while untreated animals were exposed to tap water over the same period. Food was provided ad libitum. After this period, the animals underwent i.p. fecal injection for induction of sepsis. RESULTS: Experiment A showed that higher doses of ethanol resulted in early mortality from sepsis that was correlated with the alcohol consumption (high dose = 85.7%, low dose = 14.3%, P = 0.027). In experiment B, cytokine analysis demonstrated important changes resulting from sepsis, which were further affected by ethanol exposure. In addition, glucose and creatinine levels decreased and increased, respectively, after sepsis, but a significant change occurred only in the ethanol group (P < 0.003 glucose, P < 0.01 creatinine). The levels of pro-inflammatory cytokines, interleukin-6 and tumor necrosis factor-α, increased after sepsis, but were less evident after ethanol exposure. CONCLUSION: These differences may be the result of either early mortality or an increase in the severity of the septic process. Taking into account the high mortality rate and the extreme severity of sepsis after alcohol consumption, often encouraged by advertising, a caution should be given to patients with severe infections and a history of alcohol abuse.


Subject(s)
Alcohol Drinking/blood , Alcohol Drinking/mortality , Ethanol/administration & dosage , Ethanol/toxicity , Sepsis/blood , Sepsis/mortality , Animals , Cytokines/blood , Inflammation Mediators/blood , Male , Random Allocation , Rats , Rats, Wistar
9.
Horm Metab Res ; 42(1): 23-30, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19862667

ABSTRACT

The bile acid sequestrant, colesevelam hydrochloride, is approved for glycemic control in adults with type 2 diabetes. In three double-masked, placebo-controlled studies, colesevelam hydrochloride 3.75 g/day demonstrated its glycemic-lowering properties when added to existing metformin-, insulin-, or sulfonylurea-based therapy in adults with inadequately controlled type 2 diabetes. This was a 52-week open-label extension study conducted at 63 sites in the United States and one site in Mexico to further evaluate the safety and tolerability of colesevelam hydrochloride in subjects with type 2 diabetes. All subjects who completed the three double-masked, placebo-controlled studies were eligible to enroll in this open-label extension. In total, 509 subjects enrolled and received open-label colesevelam hydrochloride 3.75 g/day for 52 weeks. Safety and tolerability of colesevelam hydrochloride was evaluated by the incidence and severity of adverse events. In total, 360 subjects (70.7%) completed the extension. Of the safety population, 361 subjects (70.9%) experienced an adverse event, most (88.1%) being mild or moderate in severity. Fifty-six adverse events (11.0%) were drug-related; the most frequent drug-related adverse events were constipation and dyspepsia. Thirty-five subjects (6.9%) discontinued due to an adverse event. Fifty-four subjects (10.6%) experienced a serious adverse event; only one was considered drug-related (diverticulitis). Seventeen subjects (3.3%) experienced hypoglycemia; most episodes were mild or moderate in severity. Glycemic improvements with colesevelam hydrochloride were seen without change in weight over 52 weeks (0.2 kg mean reduction from baseline). Colesevelam hydrochloride was safe and well-tolerated as long-term therapy for patients with type 2 diabetes.


Subject(s)
Allylamine/analogs & derivatives , Diabetes Mellitus, Type 2/drug therapy , Drug Tolerance , Hypoglycemic Agents/adverse effects , Aged , Allylamine/administration & dosage , Allylamine/adverse effects , Colesevelam Hydrochloride , Dose-Response Relationship, Drug , Double-Blind Method , Drug Administration Schedule , Drug-Related Side Effects and Adverse Reactions , Female , Humans , Hypoglycemic Agents/administration & dosage , Male , Middle Aged , Treatment Outcome
10.
Can J Physiol Pharmacol ; 87(1): 37-50, 2009 Jan.
Article in English | MEDLINE | ID: mdl-19142214

ABSTRACT

Diabetes is a complex disorder characterized by impaired insulin formation, release or action (insulin resistance), elevated blood glucose, and multiple long-term complications. It is a common endocrine disorder of humans and is associated with abnormalities of carbohydrate and lipid metabolism. There are two forms of diabetes, classified as type 1 and type 2. In type 1 diabetes, hyperglycemia is due to an absolute lack of insulin, whereas in type 2 diabetes, hyperglycemia is due to a relative lack of insulin and insulin resistance. More than 90% of people with diabetes have type 2 with varied degrees of insulin resistance. Insulin resistance is often associated with impaired insulin secretion, and hyperglycemia is a common feature in both types of diabetes, but failure to make a distinction between the types of diabetes in different animal models has led to confusion in the literature. This is particularly true in relation to cardiovascular disease in the presence of diabetes and especially the response to vascular injury, in which there are major differences between the two types of diabetes. Animal models do not completely mimic the clinical disease seen in humans. Animal models are at best analogies of the pathologic process they are designed to represent. The focus of this review is an analysis of intimal hyperplasia following catheter-induced vascular injury, including factors that may complicate comparisons between different animal models or between in vitro and in vivo studies. We examine the variables, pitfalls, and caveats that follow from the manner of induction of the injury and the diabetic state of the animal. The efficacy of selected antidiabetic drugs in inhibiting the development of the hyperplastic response is also discussed.


Subject(s)
Catheterization/adverse effects , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Type 1/pathology , Diabetes Mellitus, Type 2/pathology , Disease Models, Animal , Hypoglycemic Agents/therapeutic use , Tunica Intima/pathology , Animals , Biguanides/therapeutic use , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 1/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Hyperplasia , Niacin/therapeutic use , Nitric Oxide/physiology , PPAR alpha/agonists , PPAR gamma/agonists
11.
Metabolism ; 53(10): 1331-5, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15375790

ABSTRACT

Antidiabetic agents that augment insulin secretion can cause hypoglycemia. With the current trend toward early and aggressive treatment of patients with type 2 diabetes, the hypoglycemic potential of insulinotropic agents is of concern. This study aimed to compare the propensity of the "glinide," nateglinide, and the sulfonylurea (SU), glyburide, to elicit hypoglycemia in type 2 diabetic patients with moderately elevated fasting plasma glucose (FPG). Hyperglycemic clamps (target plasma glucose = 11.1 mmol/L) were initiated, and 30 minutes later patients received a single oral dose of nateglinide (120 mg, n = 15) or glyburide (10 mg, n = 12) in a double-blind fashion. At the end of the 2-hour clamp when the glucose infusion was terminated, plasma glucose and insulin levels were measured for 4 additional hours. The minimum plasma glucose level achieved after terminating the glucose infusion (glucose nadir) was used as an index of hypoglycemic potential. The mean (+/-SEM) glucose nadir was significantly lower in patients given glyburide (3.3 +/- 0.2 mmol/L) versus nateglinide (4.4 +/- 0.3 mmol/L, P = .025). Confirmed hypoglycemia (plasma glucose < or = 2.8 mmol/L) occurred in 2 of 12 patients given glyburide and in none of those given nateglinide. Plasma insulin levels were significantly higher from 100 to 240 minutes after clamp termination in patients given glyburide versus nateglinide. Nateglinide has less hypoglycemic potential than glyburide, suggesting that nateglinide may be a more appropriate insulinotropic agent for patients with moderate fasting hyperglycemia, such as elderly patients and those with comorbid cardiac ischemia.


Subject(s)
Cyclohexanes/therapeutic use , Diabetes Mellitus, Type 2/drug therapy , Glyburide/therapeutic use , Hypoglycemic Agents/therapeutic use , Phenylalanine/therapeutic use , Adult , Aged , Area Under Curve , Blood Glucose/metabolism , Cyclohexanes/adverse effects , Diabetes Mellitus, Type 2/blood , Double-Blind Method , Female , Glucose Clamp Technique , Glyburide/adverse effects , Humans , Hypoglycemic Agents/adverse effects , Insulin/blood , Male , Middle Aged , Nateglinide , Phenylalanine/adverse effects , Phenylalanine/analogs & derivatives
12.
Metab Syndr Relat Disord ; 2(2): 105-13, 2004 Jun.
Article in English | MEDLINE | ID: mdl-18370641

ABSTRACT

Until recently, atherosclerosis was thought to be a passive process of lipid deposition in the arterial wall, followed by progressive occlusion of the lumen, and finally plaque rupture and thrombosis. Recent data suggest the contrary-atherosclerosis is a dynamic process developing over many years, characterized by active uptake of lipids and smooth muscle proliferation, "molding" of plaque, and subject to the influence of many environmental and genetic factors. Central to these processes, both at initiation and propagation, are factors associated with inflammation. Insulin resistance (IR), the underlying cause of type 2 diabetes mellitus (DM), is also associated with elevated levels of inflammatory factors, such as C reactive protein (CRP), plasminogen activator inhibitor-1 (PAI-1), and fibrinogen. Recent studies indicate that these same factors precede and predict DM. These findings have led to the notion that the strong association of IR/DM with cardiovascular disease (CVD) may be through inflammation pathways. In this article, we review what is known about the association of inflammation with IR and atherosclerosis. We show that many of the same inflammatory factors associated with IR are present in atherosclerosis. We also discuss the underlying determinants of inflammation in these conditions.

13.
Curr Drug Targets ; 4(6): 477-86, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12866662

ABSTRACT

Morbidity and mortality from diabetes mellitus remain high despite managing the traditional risk factors. Recent data imply that the pathophysiology of macrovascular and microvascular complications involve other factors. The metabolic syndrome precedes the onset of type 2 diabetes by many years. Early treatment of individuals with this syndrome might delay the onset of diabetes and its complications. Endothelial dysfunction, subclinical inflammation and impaired fibrinolysis may contribute to progression of macrovascular as well as microvascular complications. The roles of infection and hyperhomocysteinemia are less clear but may be significant. This review discusses the current knowledge on these "non-traditional" risk factors and therapies to improve them.


Subject(s)
Cardiovascular Diseases/etiology , Diabetes Mellitus , Albuminuria/etiology , C-Reactive Protein/biosynthesis , Diabetes Complications , Diabetes Mellitus/drug therapy , Diabetes Mellitus/metabolism , Endothelium, Vascular/metabolism , Homocysteine/metabolism , Humans , Inflammation/metabolism , Insulin Resistance , Risk Factors
14.
Atherosclerosis ; 158(2): 297-301, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11583707

ABSTRACT

Hyperhomocysteinemia is a well established risk factor for cardiovascular disease, and multiple factors likely lead to abnormal regulation of plasma homocysteine in patients with diabetes. To examine a possible role for insulin and glucose in homocysteine metabolism, we examined the activity of two important enzymes of homocysteine metabolism in hepatocytes. In various tissues of six mice, methylene tetrahydrofolate reductase (MTHFR) activity was present in all tissues tested and the highest concentration (per gram) was in the brain. In contrast, cystathionine beta-synthase (CBS) activity appeared to be present only in the liver and to a small extent in the kidney. Using HEP G2 cells in culture, MTHFR activity was 3.3+/-0.8 nmol/h when the glucose concentration in the medium was 100 mg/dl and fell to 2.3+/-0.3 nmol/h when glucose was increased to 300 mg/dl. MTHFR activity was 3.4+/-0.3 nmol/h when cells were exposed to an insulin concentration of 5 mU/ml and fell to 2.8+/-0.3 nmol/h when insulin concentration was increased to 200 mU/ml (P<0.01). In contrast CBS activity increased from 0.017 to 0.13 U/ml by increasing the glucose concentration in the medium (P<0.01), but decreased from 0.04 to 0.02 (P<0.01) when the insulin concentration was increased from 5 to 200 mU/ml, respectively. We conclude that CBS and MTHFR have different tissue distributions, with CBS being present predominantly in liver and kidney, and MTHFR found in many tissues. In addition, both insulin and glucose affect the activity of the two enzymes when added to hepatocytes in vitro. If such effects occur in humans with hyperglycemia and hyperinsulinemia, then alterations in homocysteine metabolism may contribute to the accelerated macrovascular disease associated with insulin resistance or type 2 diabetes.


Subject(s)
Cystathionine beta-Synthase/metabolism , Glucose/pharmacology , Hepatocytes/enzymology , Insulin/pharmacology , Oxidoreductases Acting on CH-NH Group Donors/metabolism , Animals , Brain/enzymology , Cystathionine beta-Synthase/drug effects , Hepatocytes/drug effects , Homocysteine/metabolism , Humans , Methylenetetrahydrofolate Reductase (NADPH2) , Mice , Mice, Inbred C57BL , Oxidoreductases Acting on CH-NH Group Donors/drug effects , Tumor Cells, Cultured
15.
Metabolism ; 50(9): 1014-8, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11555831

ABSTRACT

The erythrocyte concentrations of the body's chief physiologic methyl donor S-adenosylmethionine (SAM) and of its metabolite and inhibitor S-adenosylhomocysteine (SAH), the plasma concentrations of total homocysteine (tHcy), and the activity of N(5,10) methylenetetrahydrofolate reductase (MTHFR) in lymphocytes were determined in healthy subjects and patients with diabetes mellitus without complications and at various stages of diabetic nephropathy, categorized according to the degree of progression of the disease. These groups were as follows: 1, control; 2, diabetics with no complications; 3, patients with albuminuria; 4, patients with an elevated plasma creatinine; and 5, patients on dialysis. No parameter studied exhibited significant differences between the type 1 and the type 2 diabetics. In control subjects, the blood concentrations of SAM were proportional to the activity of MTHFR; in diabetics, it was not. Consistent with previous observations, progression of nephropathy was accompanied by increased concentrations of tHcy. Increased erythrocyte concentrations of SAH, decreased erythrocyte concentrations of SAM, SAM/SAH ratios, and lymphocyte MTHFR activity also accompanied disease progression. The blood concentrations of SAH paralleled those of tHcy, while the concentrations of SAM showed a bimodal relationship with those of tHcy. These results provide further evidence that alterations in the blood concentrations of SAM and related compounds are abnormal in patients with diabetes, particularly in those with nephropathy. The deficiency of SAM may lead to methyl deficiencies, which may contribute to the high morbidity and mortality in patients with diabetic nephropathy. We have also demonstrated a decrease in lymphocyte MTHFR activity in patients with advanced nephropathy, suggesting that hyperhomocysteinemia in these patients may be due to a generalized metabolic abnormality. Further studies are needed to determine the pathogenesis of these abnormalities and whether they are present in renal failure due to causes other than diabetes or whether they are specific to diabetic nephropathy.


Subject(s)
Diabetes Mellitus/metabolism , Diabetic Nephropathies/metabolism , Lymphocytes/enzymology , Oxidoreductases Acting on CH-NH Group Donors/metabolism , S-Adenosylmethionine/blood , Adult , Albuminuria , Creatinine/blood , Diabetes Complications , Diabetic Nephropathies/complications , Diabetic Nephropathies/therapy , Disease Progression , Erythrocytes/metabolism , Female , Homocysteine/blood , Humans , Male , Methylenetetrahydrofolate Reductase (NADPH2) , Middle Aged , Reference Values , Regression Analysis , Renal Dialysis , S-Adenosylhomocysteine/blood
16.
Ann Intern Med ; 134(1): 61-71, 2001 Jan 02.
Article in English | MEDLINE | ID: mdl-11187421

ABSTRACT

The thiazolidinediones are a new class of compounds for treatment of type 2 diabetes. Troglitazone became available in the United States in 1997 but was withdrawn from the market in March 2000 because it caused severe idiosyncratic liver injury. Rosiglitazone and pioglitazone have been available since 1999. Because these drugs directly improve insulin resistance and decrease plasma insulin levels (a risk factor for coronary artery disease), they may decrease risk for cardiovascular disease in patients with type 2 diabetes. Research on the non-glucose lowering effects of troglitazone and, to a lesser extent, of rosiglitazone and pioglitazone have demonstrated changes in several cardiovascular risk factors associated with the insulin resistance syndrome. These beneficial effects include a decrease in blood pressure, correction of diabetic dyslipidemia, improvement of fibrinolysis, and decrease in carotid artery intima-media thickness. Other in vitro effects related to the ability of these agents to bind a newly described class of receptors (peroxisome proliferator-activated receptors) may also have implications for atherosclerosis. However, these drugs increase low-density lipoprotein (LDL) cholesterol levels and may favorably change LDL particle size and susceptibility to oxidation (although the implications of the latter changes are not dear). Furthermore, these drugs tend to cause weight gain. The authors' enthusiasm for these drugs has diminished somewhat because of reported adverse events, including rare liver failure. Nevertheless, because of the mechanism of action of the thiazolidinediones, clinical trials designed to determine whether they (or similar "insulin sensitizers") decrease cardiovascular events in people with type 2 diabetes will be of interest.


Subject(s)
Hypoglycemic Agents/pharmacology , Thiazoles/pharmacology , Body Weight/drug effects , Cardiovascular Diseases/prevention & control , Cardiovascular System/drug effects , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/drug therapy , Endothelium, Vascular/drug effects , Female , Hemostasis/drug effects , Humans , Hypoglycemic Agents/adverse effects , Insulin/blood , Insulin Resistance/physiology , Lipid Metabolism , Liver Failure/chemically induced , Oxidation-Reduction/drug effects , Pancreas/drug effects , Polycystic Ovary Syndrome/drug therapy , Risk Factors , Thiazoles/adverse effects
18.
Toxicol Sci ; 56(2): 431-6, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10911003

ABSTRACT

High exposures of Vietnam veterans to 2,3,7, 8-Tetrachlorodibenzo-p-dioxin, a dioxin contained in the herbicide mixture Agent Orange, have previously been demonstrated to be associated with an increased prevalence of diabetes and hyperinsulinemia in non-diabetic subjects. Sixty-nine persons were identified who were in good health and had normal glucose levels during glucose tolerance testing. These subjects lived within 25 miles of the Vertac/Hercules Superfund site located in Jacksonville, Arkansas. The blood sera lipid concentrations of TCDD for the 69 subjects ranged between 2 and 94 ppt. When subjects with blood sera lipid TCDD levels in the top 10% (TCDD > 15 ppt, n = 7) were compared to subjects with lower levels (2-15 ppt, n = 62), there were no group differences in age, obesity, gender distribution, total lipids, or glucose levels. However, plasma insulin concentrations, at fasting and 30, 60, and 120 min following a 75 g glucose load, were significantly higher in the group with high blood TCDD levels. These finding could not be explained by other known risk factors for hyperinsulinemia. The finding of the TCDD-hyperinsulinemia relationship is consistent with studies of Vietnam veterans and suggests that high blood TCDD levels may cause insulin resistance.


Subject(s)
Hyperinsulinism/chemically induced , Insulin Resistance , Polychlorinated Dibenzodioxins/toxicity , Adult , Aged , Female , Humans , Male , Middle Aged , Polychlorinated Dibenzodioxins/blood
19.
Endocr Pract ; 6(6): 435-41, 2000.
Article in English | MEDLINE | ID: mdl-11155214

ABSTRACT

OBJECTIVE: To determine whether hyperhomocysteinemia (HH) exacerbates other cardiovascular risk factors and markers of coagulation and hemostasis in patients with type 2 diabetes mellitus (DM) and whether treatment of HH with vitamins will alter these risk factors. METHODS: We measured several cardiovascular risk factors and markers of coagulation and hemostasis in patients with type 2 DM with and without HH. We also treated patients with type 2 DM and coexistent HH with high doses of folic acid and pyridoxine to determine whether this treatment would lower plasma total homocysteine concentrations as well as correct other associated cardiovascular risk factors in this population. RESULTS: Plasma levels of plasminogen activator inhibitor type 1 and fibrinogen were significantly higher in all patients with DM in comparison with control subjects (P<0.01), whether they had HH or not. No significant difference was noted between the two groups of patients with DM. The presence of hypertension and microalbuminuria did not lead to a higher plasma total homocysteine. After treatment with folic acid, 15 mg daily, and pyridoxine, 600 mg daily, fasting (basal) plasma total homocysteine declined significantly in patients with DM from 12.3 +/- 2.9 micromol/L to 9.1 +/- 1.1 micromol/L (P<0.01). The peak post-methionine load plasma total homocysteine in the patients with DM decreased from 39.9 +/- 11.4 micromol/L to 30.4 +/- 6.5 micromol/L (P<0.05). Neither fasting nor peak plasma total homocysteine changed in normal subjects. None of the cardiovascular risk factors measured changed significantly with the vitamin treatment. CONCLUSION: The coexistence of type 2 DM and HH does not lead to an exacerbation of abnormalities in the measured variables of coagulation and hemostasis. Treatment with high doses of folic acid and pyridoxine lowers the plasma total homocysteine significantly but does not improve any of the associated cardiovascular risk factors that we measured. Long-term clinical trials should be conducted to determine whether high-dose vitamin treatment will diminish the increased morbidity and mortality associated with cardiovascular disease in patients with type 2 DM.


Subject(s)
Cardiovascular Diseases/etiology , Diabetes Mellitus, Type 2/blood , Folic Acid/therapeutic use , Hyperhomocysteinemia/complications , Hyperhomocysteinemia/drug therapy , Pyridoxine/therapeutic use , Adult , Cohort Studies , Homocysteine/blood , Humans , Hyperhomocysteinemia/blood , Middle Aged , Risk Factors , Treatment Outcome
20.
Compr Ther ; 25(8-10): 418-26, 1999.
Article in English | MEDLINE | ID: mdl-10520444

ABSTRACT

Several new pharmacological agents attempt to correct abnormalities in the pathogenesis of type 2 diabetes mellitus. The availability of agents with different mechanisms of action and side-effect profiles permits the design of individualized regimens that address the various pathophysiologic abnormalities.


Subject(s)
Diabetes Mellitus, Type 2/diet therapy , Diabetes Mellitus, Type 2/drug therapy , Exercise , Hypoglycemic Agents/therapeutic use , Blood Glucose , Combined Modality Therapy , Diabetes Mellitus, Type 2/diagnosis , Dose-Response Relationship, Drug , Drug Administration Schedule , Female , Humans , Male , Prognosis , Weight Loss
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