Retinal haemodynamics in individuals with well-controlled type 1 diabetes.
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ABSTRACT:
SUBMITTER: Lorenzi M
PROVIDER: S-EPMC2170455 | biostudies-other | 2008 Feb
REPOSITORIES: biostudies-other
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Project description:AIM:Increased plasma uric acid (PUA) concentrations are associated with chronic kidney disease in type 2 diabetes (T2D) patients. The mechanisms involved remain unclear. We investigated the relation between PUA and (intra)renal haemodynamics in T2D patients without overt kidney disease. METHODS:Eighty-eight white men and women with T2D were included (age 64 (58-68) years; body mass index 30.9 (28.3-33.6) kg/m2 ; glycated haemoglobin 7.1 (6.8-7.6)%). Plasma UA and fractional excretion of UA were measured, while glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were assessed by inulin and PAH-clearance techniques, respectively. Effective renal vascular resistance was calculated (ERVR). Renal afferent and efferent arteriolar resistances and glomerular hydrostatic pressure were estimated. Relationships between PUA and fractional excretion of UA and (intra)renal haemodynamic parameters were evaluated by multivariable linear regression analyses. RESULTS:Plasma UA concentrations were at the higher end of the normal range in most participants: 342?±?68 ?mol/L or 5.7?±?1.1?mg/dL (mean?±?SD). In multivariable analyses, PUA concentrations were negatively associated with GFR (r =?-0.471; P =?0.001), ERPF (r =?-0.436; P =?0.003) and glomerular hydrostatic pressure (r =?-0.427; P =?0.003). In contrast, PUA concentrations had a positive correlation with ERVR (r =?0.474; P =?0.001), but not with efferent vascular resistance. Fractional excretion of UA was not related to renal haemodynamics. CONCLUSION:Plasma UA was negatively associated to GFR, ERPF but positively related to ERVR in T2D patients without overt renal impairment. Plasma UA-related increase in ERVR may be related to increased arterial afferent tone, which may put the kidney at risk for renal damage through ischaemia.
| S-EPMC7065078 | biostudies-literature
Project description:OBJECTIVE The potential benefits of continuous glucose monitoring (CGM) in the management of adults and children with well-controlled type 1 diabetes have not been examined. RESEARCH DESIGN AND METHODS A total of 129 adults and children with intensively treated type 1 diabetes (age range 8-69 years) and A1C <7.0% were randomly assigned to either continuous or standard glucose monitoring for 26 weeks. The main study outcomes were time with glucose level < or =70 mg/dl, A1C level, and severe hypoglycemic events. RESULTS At 26 weeks, biochemical hypoglycemia (< or =70 mg/dl) was less frequent in the CGM group than in the control group (median 54 vs. 91 min/day), but the difference was not statistically significant (P = 0.16). Median time with a glucose level < or =60 mg/dl was 18 versus 35 min/day, respectively (P = 0.05). Time out of range (< or =70 or >180 mg/dl) was significantly lower in the CGM group than in the control group (377 vs. 491 min/day, P = 0.003). There was a significant treatment group difference favoring the CGM group in mean A1C at 26 weeks adjusted for baseline (P < 0.001). One or more severe hypoglycemic events occurred in 10 and 11% of the two groups, respectively (P = 1.0). Four outcome measures combining A1C and hypoglycemia data favored the CGM group in comparison with the control group (P < 0.001, 0.007, 0.005, and 0.003). CONCLUSIONS Most outcomes, including those combining A1C and hypoglycemia, favored the CGM group. The weight of evidence suggests that CGM is beneficial for individuals with type 1 diabetes who have already achieved excellent control with A1C <7.0%.
| S-EPMC2713649 | biostudies-literature
Project description:The aim of this study was to compare retinal oxygen extraction in individuals with diabetes with no or mild non-proliferative diabetic retinopathy and healthy age- and sex-matched volunteers.A total of 24 participants with type 1 diabetes and 24 healthy age- and sex-matched volunteers were included in this cross-sectional study. Retinal oxygen extraction was measured by combining total retinal blood flow measurements using a custom-built bi-directional Doppler optical coherence tomography system with measurements of oxygen saturation using spectroscopic reflectometry. Based on previously published mathematical modelling, the oxygen content in retinal vessels and total retinal oxygen extraction were calculated.Total retinal blood flow was higher in diabetic participants (46.4 ± 7.4 ?l/min) than in healthy volunteers (40.4 ± 5.3 ?l/min, p = 0.002 between groups). Oxygen content in retinal arteries was comparable between the two groups, but oxygen content in retinal veins was higher in participants with diabetes (0.15 ± 0.02 ml O2/ml) compared with healthy control participants (0.13 ± 0.02 ml O2/ml, p < 0.001). As such, the arteriovenous oxygen difference and total retinal oxygen extraction were reduced in participants with diabetes compared with healthy volunteers (total retinal oxygen extraction 1.40 ± 0.44 vs 1.70 ± 0.47 ?l O2/min, respectively, p = 0.03).Our data indicate early retinal hypoxia in individuals with type 1 diabetes with no or mild diabetic retinopathy as compared with healthy control individuals. Further studies are required to fully understand the potential of the technique in risk stratification and treatment monitoring.ClinicalTrials.gov NCT01843114.
| S-EPMC5491565 | biostudies-literature
Project description:Intensification of glycemic control is associated with weight gain, however, less is known about weight change during the maintenance phase of glycemic management. On the basis of current models of energy homeostasis, we hypothesize that insulin use will result in less weight gain than oral antidiabetic agents in patients with well-controlled diabetes. This is a prospective cohort nested within a randomized control trial at an academic clinic, with enrollment from June 2002 to January 2005. A total of 163 patients with type 2 diabetes were enrolled after obtaining glycemic control. Insulin use was assessed by self-report at baseline. Participants were weighed at baseline and five follow-up visits over 24 months. The weight change was compared between insulin users and noninsulin users. The average (s.d.) age was 55 (11), 44% are female and 21% are black. The median duration of diabetes was 5 (0.5-10) years. At baseline, 88 participants (54%) reported insulin use with an average of 69 (6) units/day. Baseline BMI in the insulin users was 35 (6) and 33 (6) in noninsulin patients. Over 24 months, noninsulin patients gained 2.3 additional kilograms compared with insulin users (2.8 kg (6.8) vs. 0.5 kg (6.5), P = 0.065). After adjusting for age, race, sex, baseline weight, intervention status, and change in A1C, insulin users had 2.5 kg less weight gain than noninsulin users (P = 0.033). Less weight gain was observed over 24 months in insulin-treated patients. Whether this effect may be due to central catabolic effects of insulin merits additional confirmatory study and mechanistic investigation.
| S-EPMC2694404 | biostudies-other
Project description:In patients with diabetes, psychological well-being constructs (e.g., optimism, positive affect) have been associated with superior medical outcomes, including better glucose control and lower mortality rates. Well-being interventions may be well-suited to individuals with diabetes, as they are simple to deliver, broadly applicable across a range of psychological distress, and may help increase self-efficacy and motivation for diabetes self-care. This systematic review, completed using PRISMA guidelines, examined peer-reviewed studies indexed in PubMed, PsycINFO, and/or Scopus between database inception and October 2017 that investigated the effects of well-being interventions (e.g., positive psychology interventions, mindfulness-based interventions, resilience-based interventions) on psychological and physical health outcomes in individuals with Type 1 or Type 2 diabetes. The search yielded 34 articles (N = 1635 participants), with substantial variability in intervention type, measures used, and outcomes studied; the majority found the intervention to provide benefit. Overall, results indicate that a range of well-being interventions appear to have promise in improving health outcomes in this population, but the literature does not yet provide definitive data about which specific interventions are most effective. The variability in interventions and outcomes points to a need for further rigorous, controlled, and well-powered studies of specific interventions, with well-accepted, clinically relevant outcome measures.
| S-EPMC6370485 | biostudies-literature
Project description:BackgroundType 2 diabetes mellitus (T2DM) and its associated complications puts considerable strain on healthcare systems. With the global incidence of T2DM increasing, effective disease management is essential. Physical activity (PA) is a key component of T2DM management; however, rates of PA engagement are low in this population. Developing effective and sustainable interventions that encourage PA is a high priority. Electrically assisted bicycles are becoming increasingly popular and may increase PA in healthy adults. This study aimed to provide evidence of the feasibility of conducting a randomized controlled trial to evaluate the efficacy of an e-cycling intervention to increase PA and improve health in individuals with T2DM.MethodsA parallel-group two-arm randomized, waitlist-controlled pilot study was conducted. Individuals were randomized to either an e-bike intervention or standard care. The intervention incorporated two one-to-one e-bike skills training and behavioural counselling sessions delivered by a community-based cycling charity, followed by a 12-week e-bike loan with two further sessions with the instructors. Feasibility was assessed via measures related to recruitment, retention and intervention implementation. Post-intervention interviews with instructors and participants explored the acceptability of the study procedures and intervention. Clinical, physiological and behavioural outcomes were collected at baseline and post-intervention to evaluate the intervention's potential.ResultsForty participants (Mage = 57) were randomized, of which 34 were recruited from primary care practices. Thirty-five participants were retained in the trial. The intervention was conducted with high fidelity (> 80% content delivered). E-bike training provided participants with the skills, knowledge and confidence needed to e-bike independently. Instructors reported being more confident delivering the skills training than behavioural counselling, despite acknowledging its importance. The study procedures were found to be acceptable to participants. Between-group differences in change during the intervention were indicative of the interventions potential for improving glucose control, health-related quality of life and cardiorespiratory fitness. Increases in overall device measured moderate-to-vigorous PA behaviour following the intervention were found, and there was evidence that this population self-selected to e-cycle at a moderate intensity.ConclusionsThe study's recruitment, retention, acceptability and potential efficacy support the development of a definitive trial subject to identified refinements.Trial registrationISRCTN, ISRCTN67421464 . Registered 17/12/2018.
| S-EPMC10111297 | biostudies-literature
Project description:The eye provides an opportunistic "window" to view the microcirculation. There is published evidence of an association between retinal microvascular calibre and renal function measured by estimated glomerular filtration rate (eGFR) in individuals with diabetes mellitus. Beyond vascular calibre, few studies have considered other microvascular geometrical features. Here we report novel null findings for measures of vascular spread (vessel fractal dimension), tortuosity, and branching patterns and their relationship with renal function in type 2 diabetes over a mean of 3 years. We performed a nested case-control comparison of multiple retinal vascular parameters between individuals with type 2 diabetes and stable (non-progressors) versus declining (progressors) eGFR across two time points within a subset of 1072 participants from the GoDARTS study cohort. Retinal microvascular were measured using VAMPIRE 3.1 software. In unadjusted analyses and following adjustment for age, gender, systolic blood pressure, HbA1C, and diabetic retinopathy, no associations between baseline retinal vascular parameters and risk of eGFR progression were observed. Cross-sectional analysis of follow-up data showed a significant association between retinal arteriolar diameter and eGFR, but this was not maintained following adjustment. These findings are consistent with a lack of predictive capacity for progressive loss of renal function in type 2 diabetes.
| S-EPMC5834527 | biostudies-literature
Project description:ObjectiveHypoglycemia in young children with type 1 diabetes is an acute complication of intensive insulin therapy and is commonly observed in the absence of signs or symptoms. The effect of intensive treatment and patient age on sympathoadrenal responses has not been established in youth with type 1 diabetes because of difficulties in testing procedures.Research design and methodsWe developed a standardized inpatient continuous subcutaneous insulin infusion protocol to produce a progressive fall in plasma glucose concentrations in insulin pump-treated patients. Plasma glucose and counterregulatory hormone concentrations were measured in 14 young children (3 to <8 years, A1C 7.7 +/- 0.6%) vs. 14 adolescents (12 to <18 years, A1C 7.6 +/- 0.8%).ResultsPlasma glucose decreased to similar nadir concentrations in the two groups. Four young children and four adolescents never had an epinephrine response. In the four young children and five adolescents who had a modest epinephrine response, this only occurred when plasma glucose fell to <60 mg/dl. In evaluating symptom scores, 29% of parents of young children felt that their child looked hypoglycemic, even at the lowest plasma glucose concentrations. Adolescents were better able to detect symptoms of hypoglycemia. In comparison with our data, epinephrine response to hypoglycemia in 14 nondiabetic adolescents studied at the Children's Hospital of Pittsburgh was higher.ConclusionsThese data suggest that even young children and adolescents with type 1 diabetes are prone to develop hypoglycemia-associated autonomic failure regardless of duration. Whether these abnormalities can be reversed using continuous glucose monitoring and closed-loop insulin delivery systems awaits further study.
| S-EPMC2768200 | biostudies-literature
Project description:We determined the impact of a remote blood glucose telemonitoring program with feedback in type 2 diabetes mellitus patients fasting during Ramadan compared to conventional self-monitoring method. A twelve-week cluster randomised study, with 85 participants who wish to fast for at least 15 days during Ramadan was conducted. Self-measurement and transmission of blood glucose results were performed six times daily during Ramadan. Results were transmitted to a secure website for review with feedback from case manager if necessary. The control group received usual care. The main outcome was the number of participants experiencing hypoglycaemia during Ramadan and at the end of the study. During Ramadan, the number of participants reporting hypoglycaemia was significantly lower in the telemonitoring group [Odds ratio (OR): 0.186, 95% confidence interval: 0.04-0.936; p?=?0.04]. Similarly, the proportion of participants reporting symptomatic hypoglycaemia at the end of the study was significantly lower in the telemonitoring group (OR: 0.257, 95% CI: 0.07-0.89; p?=?0.03). A reduction of 1.07% in glycated haemoglobin levels was observed in the telemonitoring group compared to 0.24% in the control group (p?<?0.01). Overall, telemonitoring was a useful adjunct to reduce the risk of hypoglycaemia during Ramadan with no deterioration in glycaemic control.
| S-EPMC5579057 | biostudies-literature
Project description:The composition of the aqueous humor of patients with type 2 diabetes is relevant to understanding the underlying causes of eye-related comorbidities. Information on the composition of aqueous humor in healthy subjects is limited due to the lack of adequate controls. To carry out a metabolomics study, 31 samples of aqueous humor from healthy subjects without ocular pathology, submitted to refractive surgery and seven samples from patients with type 2 diabetes without signs of ocular pathology related to diabetes were used. The level of 25 molecules was significantly (p < 0.001) altered in the aqueous humor of the patient group. The concentration of a single molecule, N-acetylornithine, makes it possible to discriminate between control and diabetes (sensitivity and specificity equal to 1). In addition, receptor operating characteristic curve and principal component analysis for the above-mentioned six molecules yielded significantly (p < 0.001) altered in the aqueous humor of the patient group. In addition, receptor operating characteristic curve and principal component analysis for six compounds yielded cut-off values and remarkable sensitivity, specificity, and segregation ability. The altered level of N-acetylornithine may be due to an increased amount of acetate in diabetes. It is of interest to further investigate whether this alteration is related to the pathogenesis of the disease. The increase in the amino form of pyruvate, alanine, in diabetes is also relevant because it could be a means of reducing the formation of lactate from pyruvate.
| S-EPMC9658658 | biostudies-literature