Time of Day When Type 1 Diabetes Patients With Eating Disorder Symptoms Most Commonly Restrict Insulin.

OBJECTIVE: Restricting insulin to lose weight is a significant problem in the clinical management of type 1 diabetes (T1D). Little is known about this behavior or how to effectively intervene. Identifying when insulin restriction occurs could allow clinicians to target typical high-risk times or formulate hypotheses regarding factors that influence this behavior. The current study investigated the frequency of insulin restriction by time of day. METHODS: Fifty-nine adults with T1D and eating disorder symptoms completed 72 hours of real-time reporting of eating and insulin dosing with continuous glucose monitoring. We used a generalized estimating equation model to test the global hypothesis that frequency of insulin restriction (defined as not taking enough insulin to cover food consumed) varied by time of day, and examined frequency of insulin restriction by hour. We also examined whether patterns of insulin restriction for 72 hours corresponded with patients' interview reports of insulin restriction for the past 28 days. RESULTS: Frequency of insulin restriction varied as a function of time (p = .016). Insulin restriction was the least likely in the morning hours (6:00-8:59 AM), averaging 6% of the meals/snacks consumed. Insulin restriction was more common in the late afternoon (3:00-5:59 PM), peaking at 29%. Insulin was restricted for 32% of the meals/snacks eaten overnight (excluding for hypoglycemia); however, overnight eating was rare. Insulin restriction was associated with higher 120-minute postprandial blood glucose (difference = 44.4 mg/dL, 95% confidence interval = 22.7-68.5, p < .001) and overall poorer metabolic control (r = 0.43-0.62, p's < .01). Patients reported restricting insulin for a greater percentage of meals and snacks for the past 28 days than during the 72 hour real-time assessment; however, the reports were correlated (Spearman's ρ = 0.46, p < .001) and accounted for similar variance in HbA1c (34% versus 35%, respectively). CONCLUSIONS: Findings suggest that insulin restriction may be less likely in the morning, and that late afternoon is a potentially important time for additional therapeutic support. Results also suggest that systematic clinical assessment and treatment of overnight eating might improve T1D management.

Associations between central nervous system serotonin, fasting glucose, and hostility in African American females.

BACKGROUND: Previous research has shown an association between hostility and fasting glucose in African American women. Central nervous system serotonin activity is implicated both in metabolic processes and in hostility related traits. PURPOSE: The purpose of this study is to determine whether central nervous system serotonin influences the association between hostility and fasting glucose in African American women. METHODS: The study consisted of 119 healthy volunteers (36 African American women, 27 White women, 21 White males, and 35 African American males, mean age 34 ± 8.5 years). Serotonin related compounds were measured in cerebrospinal fluid. Hostility was measured by the Cook-Medley Hostility Scale. RESULTS: Hostility was associated with fasting glucose and central nervous system serotonin related compounds in African American women only. Controlling for the serotonin related compounds significantly reduced the association of hostility to glucose. CONCLUSIONS: The positive correlation between hostility and fasting glucose in African American women can partly be explained by central nervous system serotonin function.

Disinhibited eating and weight-related insulin mismanagement among individuals with type 1 diabetes.

OBJECTIVE: Withholding insulin for weight control is a dangerous practice among individuals with type 1 diabetes; yet little is known about the factors associated with this behavior. Studies of nondiabetic individuals with weight concerns suggest that eating in a disinhibited manner (e.g., binge eating) predicts the use of maladaptive compensatory strategies (e.g., self-induced vomiting). The purpose of this study was to test whether individuals with type 1 diabetes are less restrained in their eating when they think their blood glucose (BG) is low and whether this contributes to insulin omission for weight control purposes and subsequently higher hemoglobin A1c (HbA1c). METHODS: Two-hundred and seventy-six individuals with type 1 diabetes completed an online survey of eating behaviors, insulin dosing and most recent HbA1c. We used structural equation modeling to test the hypothesis that disinhibited eating when blood sugar is thought to be low predicts weight-related insulin mismanagement, and this, in turn, predicts higher HbA1c. RESULTS: The majority of participants endorsed some degree of disinhibition when they think their blood glucose is low (e.g., eating foods they do not typically allow) and corresponding negative affect (e.g., guilt/shame). The frequency of disinhibited eating was positively associated with weight-related insulin mismanagement. Controlling for age, sex, education, and insulin pump use, the model explained 31.3% of the variance in weight-related insulin mismanagement and 16.8% of the variance in HbA1c. CONCLUSION: Addressing antecedents to disinhibited eating that are unique to type 1 diabetes (e.g., perceived BG level) and associated guilt or shame may reduce weight-related insulin omission.

Central nervous system serotonin and clustering of hostility, psychosocial, metabolic, and cardiovascular endophenotypes in men.

OBJECTIVE: To use measures of cerebrospinal fluid (CSF) 5-hydroxyindoleacetic acid (5HIAA) and genotype of a functional polymorphism of the monoamine oxidase A gene promoter (MAOA-uVNTR) to study the role of central nervous system (CNS) serotonin in clustering of hostility, other psychosocial, metabolic and cardiovascular endophenotypes. METHODS: In 86 healthy male volunteers, we evaluated CSF levels of the primary serotonin metabolite 5HIAA and MAOA-uVNTR genotype for association with a panel of 29 variables assessing hostility, other psychosocial, metabolic, and cardiovascular endophenotypes. RESULTS: The correlations of 5HIAA with these endophenotypes in men with more active MAOA-uVNTR alleles were significantly different from those of men with less active alleles for 15 of the 29 endophenotypes. MAOA-uVNTR genotype and CSF 5HIAA interacted to explain 20% and 22% of the variance, respectively, in scores on one factor wherein high scores reflected a less healthy psychosocial profile and a second factor wherein high score reflected increased insulin resistance, body mass index, blood pressure and hostility. In men with less active alleles, higher 5HIAA was associated with more favorable profiles of hostility, other psychosocial, metabolic and cardiovascular endophenotypes; in men with more active alleles, higher 5HIAA was associated with less favorable profiles. CONCLUSIONS: These findings indicate that, in men, indices of CNS serotonin function influence the expression and clustering of hostility, other psychosocial, metabolic and cardiovascular endophenotypes that have been shown to increase risk of developing cardiovascular disease. The findings are consistent with the hypothesis that increased CNS serotonin is associated with a more favorable psychosocial/metabolic/cardiovascular profile, whereas decreased CNS serotonin function is associated with a less favorable profile.

Hostility and minimal model of glucose kinetics in African American women.

OBJECTIVE: To explore the underlying physiology of hostility (HOST) and to test the hypothesis that HOST has a greater impact on fasting glucose in African American (AA) women than it does on AA men or white men or women, using an intravenous glucose tolerance test (IVGTT) and the minimal model of glucose kinetics. METHODS: A total of 115 healthy subjects selected for high or low scores on the 27 item Cook Medley HOST Scale underwent an IVGTT. Fasting nonesterified fatty acids (NEFA) levels were measured before the IVGTT. Catecholamine levels were measured 10 minutes into the IVGTT. RESULTS: Moderation by group (AA women versus others) of HOST was found for glucose effectiveness (Sg, p = .02), acute insulin response (AIRg, p = .02), and disposition index (DI, p = .02). AA women showed a negative association between HOST and both Sg (beta = -0.45, p = .04) and DI (beta = -0.49, p = .02), controlling for age and body mass index. HOST was also associated with changes in epinephrine (beta = 0.39, p = .05) and fasting NEFA (beta = 0.44, p = .02) in the AA women. Controlling for fasting NEFA reduced the effect of HOST on both Sg and DI. CONCLUSIONS: This study shows that HOST is related to decreased DI, a measure of pancreatic compensation for increased insulin resistance as well as decreased Sg, a measure of noninsulin-mediated glucose transport compared in AA women. These effects are partly mediated by the relationship of HOST to fasting NEFA.

Hostility and fasting glucose in African American women.

OBJECTIVE: To examine whether the relationship of hostility (HOST) to fasting glucose indices is moderated by sex and race. HOST has been associated with abnormalities in glucose metabolism. Prior studies suggested that this association may be more prevalent in women and in African American (AA) individuals. METHODS: A total of 565 healthy AA and white (W) men and women (mean age = 33 +/- 6 years) were assessed. HOST was measured by the 27-item version of the Cook Medley HOST Scale. The moderating effects of sex and race were evaluated for the associations of HOST to fasting glucose, insulin, and insulin sensitivity (HOMA-IR). RESULTS: Analysis showed a moderating effect of sex and race on the association of HOST to fasting glucose (p = .03), but not for insulin (p = .12). Analysis of HOMA-IR revealed a trend (p = .06) for the interaction. Stratified analyses by race and sex revealed a positive association between HOST and fasting glucose only in AA women, which remained significant after controlling for age and body mass index. CONCLUSION: A relationship between HOST and fasting glucose was evident in AA women only, a group that has twice the risk of developing Type 2 diabetes compared with W women. Further studies are needed to elucidate the mechanisms by which HOST may affect glucose metabolism in AA women.

Childhood socioeconomic status and serotonin transporter gene polymorphism enhance cardiovascular reactivity to mental stress.

OBJECTIVE: To test the hypothesis that low socioeconomic status (SES) and the 5HTTLPR L allele are associated with increased cardiovascular reactivity (CVR) to stress in a larger sample and that SES and 5HTTLPR genotypes interact to enhance CVR to stress. CVR to mental stress has been proposed as one mechanism linking stress to the pathogenesis of cardiovascular disease. The more transcriptionally efficient long (L) allele of a polymorphism of the serotonin transporter gene promoter (5HTTLPR) has been found associated with increased risk of myocardial infarction. We found the long allele associated with larger CVR to mental stress in a preliminary study of 54 normal volunteers. METHODS: Subjects included 165 normal community volunteers stratified for race, gender, and SES, who underwent mental stress testing. RESULTS: Childhood SES as indexed by Father's Education Level was associated with larger systolic blood pressure (SBP) (p < .05) and diastolic blood pressure (DBP) (p = .01) responses to mental stress. The L allele was associated with larger SBP (p = .04), DBP (p < .0001), and heart rate (p = .04) responses to mental stress compared with the short (S) allele. Subjects with the SS genotype and high Father's Education exhibited smaller SBP (5.2 mm Hg) and DBP (2.9 mm Hg) responses than subjects with LL genotype and low Father's Education (SBP = 13.3 mm Hg, p = .002; DBP = 9.7 mm Hg, p < .0001). CONCLUSIONS: Both the 5HTTLPR long allele and low SES, particularly during childhood, are associated with increased CVR to mental stress, which could account, at least in part, for the increased cardiovascular disease risk associated with these characteristics. If confirmed in further research, these characteristics could be used to identify persons who might benefit from preventive interventions.

Associations of a regulatory polymorphism of monoamine oxidase-A gene promoter (MAOA-uVNTR) with symptoms of depression and sleep quality.

OBJECTIVE: To examine the relationships among the variable number of tandem repeats in the monoamine oxidase-A linked polymorphic region allelic variation (MAOA-uVNTR) and the symptoms of depression and sleep quality. The monoamine oxidase-A (MAOA) gene, which plays a vital role in degradation of neurotransmitters such as serotonin, norepinephrine, and dopamine, contains a polymorphism in its promoter region (MAOA-uVNTR) that affects transcriptional efficiency. MAOA-uVNTR genotype has been associated with both psychological and physical measures. METHODS: The sample consisted of 74 males enrolled in a case/control study of caregivers for relatives with dementia. Age- and race-adjusted linear regression models were used to examine the association between low versus high MAOA-uVNTR activity alleles, symptoms of depression (Center for Epidemiological Studies of Depression), and sleep quality ratings (Pittsburgh Sleep Quality Index). RESULTS: MAOA-uVNTR alleles associated with less transcriptional activity were related to increased symptoms of depression (p < .04; Cohen's d = 0.52) and poorer sleep quality (p < .04; Cohen's d = 0.31). CONCLUSIONS: Individuals with less active MAOA-uVNTR alleles may be at increased risk for depressive symptoms and poor sleep.

Changes in depressive symptoms and glycemic control in diabetes mellitus.

OBJECTIVE: To investigate if changes in depressive symptoms would be associated with changes in glycemic control over a 12-month period in patients with Type 1 and Type 2 diabetes. METHODS: Ninety (Type 1 diabetes, n = 28; Type 2 diabetes, n = 62) patients having Beck Depression Inventory (BDI) levels of >10 were enrolled in the study. Of those 90 patients, 65 patients completed a 12-week cognitive behavioral therapy intervention. BDI was assessed at baseline and thereafter biweekly during 12 months. Hemoglobin (HbA1c) and fasting blood glucose levels were assessed at baseline and at four quarterly in-hospital follow-up visits. Linear mixed-model analysis was applied to determine the effects of time and diabetes type on depressive symptoms, HbA1c levels, and fasting glucose levels. RESULTS: Mean and standard deviation baseline BDI and HbA1c levels were 17.9 +/- 5.8 and 7.6 +/- 1.6, respectively, with no significant difference between patients with Type 1 and Type 2 diabetes. Mixed-model regression analysis found no difference between the groups with Type 1 and Type 2 diabetes in the within-subject effect of BDI score on HbA1c or fasting glucose levels during the study. Depressive symptoms decreased significantly (p = .0001) and similarly over a 12-month period in both patients with Type 1 and Type 2 diabetes, whereas HbA1c and fasting glucose levels did not change significantly over time in either group. CONCLUSION: Changes in depressive symptoms were not associated with changes in HbA1c or fasting glucose levels over a 1-year period in either patients with Type 1 or Type 2 diabetes.

Neighborhood characteristics moderate effects of caregiving on glucose functioning.

OBJECTIVE: Adverse neighborhood environments and caregiving for a relative with dementia are both stressors that have been associated with poor health. The present study examined the extent to which three self-report measures of neighborhood characteristics interact with caregiving status (caregiver versus noncaregiver) to modify an important stress related health outcome: plasma glucose. METHODS: The study sample consisted of 147 community recruited caregivers and 147 participants who did not have caregiving responsibilities. We hypothesized that negative neighborhood characteristics would magnify effects of caregiving on plasma glucose levels. Regression analyses were conducted to examine the interaction of three neighborhood characteristic measures with caregiving status in predicting fasting plasma glucose (FPG) and glycosylated hemoglobin concentration (HbA1c), with control for age, race, gender, relation to care recipient (spouse or relative), body mass index, income, and education. RESULTS: Of the three neighborhood measures, the one reflecting crime concerns significantly moderated the effect of caregiving on FPG (p < .002) and HbA1c (p < .001). For participants with better neighborhood characteristics, caregivers and noncaregivers were similar with respect to indicators of glucose metabolism; however, for participants with worse neighborhood characteristics, caregivers had higher levels of FPG and HbA1c, as compared with noncaregivers. CONCLUSIONS: Poor health outcomes, such as impaired glucose control, may be found among caregivers who fear neighborhood crime.

Treatment regimen determines the relationship between depression and glycemic control.

UNLABELLED: Several recent studies have suggested that depression is related to poorer glycemic control in patients with type 1 diabetes, but not in type 2 diabetes. We hypothesize that complexity of self-care regimen rather than the type of diabetes, is more important in determining this relationship of depression to glycemic control. METHODS: One thousand thirty-four adults with diabetes were recruited for the study. These patients were treated with: diet and exercise, oral medications, oral medications and insulin, 1-2 daily injections of insulin, and > or =3 daily injections. All participants completed the Beck depression inventory (BDI) and had a hemoglobin A(1c) (HbA(1c)) performed as part of routine clinical care. RESULTS: Pearson correlations between BDI scores and HbA(1c) were low and insignificant in all groups (0.015< or =r< or =0.066) except for those administering three or more daily shots of insulin (r=0.284; p=0.034). DISCUSSION: The results of this study clearly show that while depressive symptoms are significantly correlated to glycemic control in patients taking three or more insulin injections per day, there is no relationship in patients who are taking fewer than three injections per day.

Distinct properties and advantages of a novel peroxisome proliferator-activated protein [gamma] selective modulator.

Antidiabetic thiazolidinediones (TZDs) and non-TZD compounds have been shown to serve as agonists of the peroxisome proliferator-activated receptor gamma (PPARgamma). Here, we report the identification and characterization of a novel non-TZD selective PPARgamma modulator (nTZDpa). nTZDpa bound potently to PPARgamma with high selectivity vs. PPARalpha or PPARdelta. In cell-based assays for transcriptional activation, nTZDpa served as a selective, potent PPARgamma partial agonist and was able to antagonize the activity of PPARgamma full agonists. nTZDpa also displayed partial agonist effects when its ability to promote adipogenesis in 3T3-L1 cells was evaluated. Assessment of protein conformation using protease protection or solution nuclear magnetic resonance spectroscopy methods showed that nTZDpa produced altered PPARgamma conformational stability vs. full agonists, thereby establishing a physical basis for its observed partial agonism. DNA microarray analysis of RNA from 3T3-L1 adipocytes treated with nTZDpa or several structurally diverse PPARgamma full agonists demonstrated qualitative differences in the affected gene expression profile for nTZDpa. Chronic treatment of fat-fed, C57BL/6J mice with nTZDpa or a TZD full agonist ameliorated hyperglycemia and hyperinsulinemia. However, unlike the TZD, nTZDpa caused reductions in weight gain and adipose depot size. Feed efficiency was also substantially diminished. Unlike TZDs, nTZDpa did not cause cardiac hypertrophy in mice. When a panel of PPARgamma target genes was examined in white adipose tissue, nTZDpa produced a different in vivo expression pattern vs. the full agonist. These findings establish that novel selective PPARgamma modulators can produce altered receptor conformational stability leading to distinctive gene expression profiles, reduced adipogenic cellular effects, and potentially improved in vivo biological responses. Such compounds may lead to preferred therapies for diabetes, obesity, or metabolic syndrome.

Stress management improves long-term glycemic control in type 2 diabetes.

OBJECTIVE: There is conflicting evidence regarding the utility of stress management training in the treatment of diabetes. The few studies that have shown a therapeutic effect of stress management have used time-intensive individual therapy. Unfortunately, widespread use of such interventions is not practical. The aim of the present investigation is to determine whether a cost-effective, group-based stress management training program can improve glucose metabolism in patients with type 2 diabetes and to determine whether a particular subset of patients is more likely to get positive results. RESEARCH DESIGN AND METHODS: Patients with type 2 diabetes were randomized to undergo a five-session group diabetes education program with or without stress management training. Participants (n = 108) were followed for 1 year, during which HbA(1c) tests and questionnaires assessing perceived stress, anxiety, and psychological health were administered at regular intervals to evaluate treatment effects. RESULTS: Stress management training was associated with a small (0.5%) but significant reduction in HbA(1c). Compliance with the treatment regimen decreased over time but was similar to that seen in patients receiving stress management for other reasons in the clinic. Trait anxiety (a measure of stable individual differences in anxiety proneness) did not predict response to treatment, showing that highly anxious patients did not derive more benefit from training. CONCLUSIONS: The current results indicate that a cost-effective, group stress management program in a "real-world" setting can result in clinically significant benefits for patients with type 2 diabetes.

Hostility, race, and glucose metabolism in nondiabetic individuals.

OBJECTIVE: The present study was designed to determine whether hostility is differentially related to measures of glucose metabolism in African-Americans and Caucasians. RESEARCH DESIGN AND METHODS: The relationship of hostility, as measured by a subset of the Cook-Medley hostility scale (CMHOST) inventory items, to various parameters of glucose metabolism were examined in a young, healthy sample of male and female African-American and Caucasian volunteers. Fasting blood samples were collected during an inpatient admission, at which time the CMHOST was also administered. RESULTS: In the entire sample, the CMHOST was found to be significantly correlated with fasting glucose and insulin sensitivity, as measured by the homeostatic model assessment (HOMA). However, the relationship of hostility to these parameters of glucose metabolism was different in African-American and Caucasian subjects. Hostility was significantly related to fasting glucose in African-Americans and to insulin sensitivity and fasting insulin in Caucasian subjects. The relationship of hostility to insulin sensitivity and fasting insulin was partially dependent on BMI in Caucasians, but the relationship of hostility to fasting glucose was unrelated to BMI in African-Americans. CONCLUSIONS: Our data suggest that the relationship of hostility to measures of glucose metabolism is mediated differently in these two ethnic groups. Therefore, hostility seems to be part of a constellation of risk-related behaviors related to BMI in Caucasians but independently related to fasting glucose in African-Americans.

Momentary Predictors of Insulin Restriction Among Adults With Type 1 Diabetes and Eating Disorder Symptomatology.

OBJECTIVE: Individuals with type 1 diabetes who restrict insulin to control weight are at high risk for diabetes-related complications and premature death. However, little is known about this behavior or how to effectively intervene. The aim of the current study was to identify predictors of insulin restriction in the natural environment that might inform new treatment directions. RESEARCH DESIGN AND METHODS: Eighty-three adults with type 1 diabetes and a range of eating disorder symptomatology completed 3 days of ecological momentary assessment. Participants reported emotions, eating, and insulin dosing throughout the day using their cellular telephone. Linear mixed models were used to estimate the effects of heightened negative affect (e.g., anxiety) before eating and characteristics of the eating episode (e.g., eating a large amount of food) on the risk of insulin restriction. RESULTS: Individuals who reported greater-than-average negative affect (general negative affect and negative affect specifically about diabetes) during the study period were more likely to restrict insulin. Momentary increases in anxiety/nervousness and guilt/disgust with self before eating (relative to an individual's typical level) further increased the odds of restricting insulin at the upcoming meal. Insulin restriction was more likely when individuals reported that they broke a dietary rule (e.g., "no desserts"). CONCLUSIONS: Results suggest that insulin restriction might be decreased by helping patients with type 1 diabetes respond effectively to heightened negative affect (e.g., anxiety, guilt) and encouraging patients to take a less rigid, punitive approach to diabetes management.

Behavioral treatment of chronic low back pain: clinical outcome and individual differences in pain relief.

The response of 111 chronic low back pain patients to a comprehensive behavioral treatment program emphasizing relaxation procedures is examined. Over the course of treatment, significant reductions were obtained on measures of subjective tension, EMG activity, and pain. Many patients also decreased their intake of analgesic/narcotic agents and reported an increase in activity level. In order to examine individual differences in pain relief, the 28 patients who had the greatest decreases in pain were compared to those who had the least decreases in pain. Patients who had the best outcome in terms of pain relief were significantly more likely to show improvements in other outcome measures. In addition, these patients rated their pain initially as more severe, had continuous pain for fewer years, and were less likely to be on disability or to have had multiple surgical procedures. These results are discussed in the light of recent data from other behavioral treatment studies with chronic low back pain patients and implications for behavioral assessment and treatment are discussed.

Fat, carbohydrate, and calories in the development of diabetes and obesity in the C57BL/6J mouse.

We have previously shown that the C57BL/6J (B6) mouse will develop obesity and diabetes if raised on a high-fat diet. Because high fat feeding is associated with hyperphagia, the present study was designed to separate the effects of fat from those of excess caloric consumption in this animal model. B6 mice were fed a low-fat diet (LF group) diet, high-fat diet (HF group) diet, or high-fat-restricted diet (HFR group), in which intake animals were pair-fed a high-fat diet to caloric level consumed by LF for 11 weeks. Within 3 weeks, HFR were significantly heavier than LF and, after 11 weeks, weight and glucose levels, but not insulin, were significantly increased in HFR when compared to LF. Body composition analysis showed the weight increase in HFR arose from an increase in percent fat consumed. We conclude that reducing the number of kilocalories consumed from a high-fat diet attenuates but does not prevent the development of type 2 diabetes and obesity in the B6 mouse.

Genetic vulnerability to diet-induced obesity in the C57BL/6J mouse: physiological and molecular characteristics.

The development of the metabolic syndrome in an increasing percentage of the populations of Western societies, particularly in the United States, requires valid models for establishing basic biochemical changes and performing preclinical studies on potential drug targets. The C57BL/6J mouse has become an important model for understanding the interplay between genetic background and environmental challenges such as high-fat/high-calorie diets that predispose to the development of the metabolic syndrome. This review highlights metabolic and signal transduction features that are altered during the course of disease progression, many of which mirror the human situation.

Pilot Study of Caffeine Abstinence for Control of Chronic Glucose in Type 2 Diabetes.

BACKGROUND: A growing body of evidence suggests that caffeinated beverages may impair chronic glucose control in type 2 diabetes. This pilot study tested the chronic effects of caffeine abstinence on glucose control in type 2 diabetic patients who were daily coffee drinkers. METHODS: Twelve coffee drinkers (six males) with established type 2 diabetes participated. Seven (five males) completed 3 months of total caffeine abstinence. Measures of chronic glucose control, long-term (hemoglobin A1c [HbA1c]) and short-term (1,5-anhydroglucitol [1,5-AG]), were collected at baseline and during follow-up. Abstinence was established by diaries confirmed by saliva caffeine assays. RESULTS: Abstinence produced significant decreases in HbA1c and increases in 1,5-AG, both indicating improvements in chronic glucose control. Fasting glucose and insulin did not change, nor were changes in body weight observed. CONCLUSIONS: Although preliminary, these results suggest that caffeine abstinence may be beneficial for patients with type 2 diabetes. This hypothesis should be confirmed in larger controlled clinical trials.