Nontransfusional iron overload in thalassemia: association with hereditary hemochromatosis.
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Adult↗
Biomedical subjects
B M Singh
Publications and source records attributed to B M Singh.
High variability of glycated hemoglobin concentrations in patients with IDDM followed over 9 years. What is the best index of long-term glycemic control?
OBJECTIVE: To determine variability of long-term glycemic control in patients with IDDM. RESEARCH DESIGN AND METHODS: A retrospective analysis of HbA1 among 122 IDDM patients followed over 9 years. RESULTS: Annual group mean HbA1 ranged from 8.4 to 9.3% with large standard deviations (1.7-2.0%), indicating marked variability among individuals. Fluctuations of more than +/- 1% HbA1 occurred in 50% of the patients year to year, and over 9 years the minimum-maximum range was > 3 and > 5% HbA1 in 55 and 11% of patients, respectively. In any one year, 22-43% of patients had HbA1 < 8%, but over 9 years only 3.3% were consistently < 8%. Groups divided according to baseline HbA1 of < 8, 8-10, and > 10% were significantly separated over 9 years by frequency distribution analysis of individual mean HbA1 but were indistinguishable when analyzed by individual HbA1 interquartile range (measure of variability). CONCLUSIONS: High variability of long-term glycemic control is a marked feature of IDDM, the extent of which may be relevant to microvascular risk.
Adult↗
A simple measure of insulin resistance.
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Blood Glucose↗
Effect of advertising on awareness of symptoms of diabetes among the general public: the British Diabetic Association Study.
OBJECTIVE: To determine the impact of posters advertising symptoms of diabetes on public knowledge of these symptoms. DESIGN: Structured street interviews of members of the general public before, at the end of, and 10 weeks after a campaign advertising the main symptoms of diabetes. SETTING: Basingstoke and Wolverhampton. SUBJECTS: Three samples of 1000 members of the general public were interviewed. Samples were selected randomly but stratified to match the local population's age (20-75), sex, social class, and racial characteristics. MAIN OUTCOME MEASURES: Knowledge of symptoms of diabetes; perceived seriousness of diabetes; and induction of anxiety about symptoms in the target population. RESULTS: Advertising significantly raised knowledge (without prompting) of symptoms: thirst, 245 before v 411 at end of campaign (P < 0.0001) v 341 after (P = 0.0012 v before); polyuria, 72 v 101 (P = 0.0211) v 92 (P = 0.5169); lethargy, 180 v 373 (P < 0.0001) v 298 (P < 0.0001); knowledge of weight loss and visual disturbance was unaffected. The number of subjects lacking knowledge of any symptoms was reduced from 550 to 388 (P < 0.0001). The perceived seriousness of diabetes was unaffected (mean 7.6 in each phase on a scale of 1 (not) to 10 (very). Before advertising, 449 (45%) claimed to have one or more symptoms of diabetes, but this number fell at the end of the campaign (403; P = 0.0419) and 10 weeks afterwards (278; P < 0.0001). CONCLUSIONS: An advertising campaign raised public knowledge of diabetes symptoms without inducing fear of diabetes or anxiety about symptoms. Its potential for achieving earlier detection of non-insulin dependent diabetes should be evaluated.
Adult↗
Insulin resistance in the regulation of lipolysis and ketone body metabolism in non-insulin dependent diabetes is apparent at very low insulin concentrations.
The insulin sensitivity of intermediary metabolism was studied in 8 non-obese men with well-controlled diet-treated non-insulin dependent diabetes (NIDDM) using a low dose incremental insulin infusion (basal, 0.005 and 0.01 U/kg h-1). Results were compared to 8 healthy male control subjects matched (NIDDM vs. controls, mean +/- S.E.M.) for age (56 +/- 3 vs. 54 +/- 3 years, NS) and body mass index (24.6 +/- 0.7 vs. 25.3 +/- 0.5 kg/m2, NS). Basal fasting concentrations of insulin (4.7 +/- 0.8 vs. 3.2 +/- 0.8 mU/l, NS), glucose, total ketone bodies (TKB), and non-esterified fatty acids (NEFA) were not significantly different between the groups but glycerol concentrations were significantly elevated in NIDDM patients (0.072 +/- 0.007 vs. 0.049 +/- 0.003 mmol/l, P < 0.05). During incremental insulin infusion, plasma insulin concentrations rose to 12.8 +/- 1.5 vs. 10.0 +/- 1.0 mU/l in NIDDM patients vs. control and metabolite concentrations fell significantly (P < 0.001). Significant linear dose-response relationships were found between plasma insulin (log) and glucose, TKB (log), NEFA, and glycerol concentrations by analysis of variance applied to regression (all P < 0.001). For glucose and TKB (log), the group regression lines were parallel but were significantly right-shifted in the NIDDM group (P < 0.001). In contrast, the relationships of insulin (log) and both glycerol and NEFA concentrations converged over the observed range of insulin concentrations. Significant displacement of glycerol and NEFA dose-response relationships were found in NIDDM patients at an insulin concentration of 5 mU/l (P < 0.001) but not at 12.5 mU/l.(ABSTRACT TRUNCATED AT 250 WORDS)
Analysis of Variance↗
Delayed diagnosis in non-insulin dependent diabetes mellitus.
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Diabetes Mellitus, Type 2↗
Effects of morbid obesity on insulin clearance and insulin sensitivity in several aspects of metabolism as assessed by low-dose insulin infusion.
Obesity is associated with impaired insulin action in glucose disposal, but not necessarily in other aspects of intermediary metabolism or insulin clearance. Sixteen morbidly obese and 14 normal-weight subjects (body mass index, 51.2 +/- 11.5 v 22.1 +/- 2.2 kg.m-2; mean +/- SD) were studied with sequential, low-dose, incremental insulin infusion with estimation of glucose turnover. In obese patients, basal plasma insulin was higher (10.5 +/- 3.8 v 2.4 +/- 3.0 mU.L-1, P less than .001) and remained elevated throughout infusion (F = 492, P less than .001), as did C-peptide (F = 22.7, P less than .001). Metabolic clearance rate for insulin (MCRI) at the highest infusion rate was similar (1,048 +/- 425 v 1,018 +/- 357 mL.m-2.min-1, NS). Basal hepatic glucose production in obese subjects was less than in normal-weight subjects (270 +/- 108 v 444 +/- 68 mumol.m-2.min-1, P less than .01), as was the basal metabolic clearance rate for glucose (MCRG, 77 +/- 26 v 108 +/- 31 mL.m-2.min-1, P less than .05). Insulin infusion caused blood glucose to decrease less in the obese patients (1.4 +/- 0.5 v 1.9 +/- 0.5 mmol.L-1, P less than .05); hepatic glucose production was appropriately suppressed in them by hyperinsulinemia, but their insulin-mediated glucose disposal was reduced (1.67 [0.79] v 4.45 [2.13] mL.m-2.min-1/mU.L-1, P less than .01). Concentrations of nonesterified fatty acids (NEFA), glycerol, and ketones were elevated throughout the insulin infusions in obese patients, despite the higher insulin concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
Metabolic effects of monomeric insulin analogues of different receptor affinity.
The effects of two monomeric insulin analogues of differing receptor affinities (human insulin = 100%) B9Asp-B27Glu-insulin (18%) and B10Asp-insulin (327%) were each compared with human insulin in two groups of 10 normal men when infused at equimolar low doses (1.0 and 2.0 pmol kg-1 min-1). The metabolic clearance rate under steady state conditions was highest for the analogue with the highest receptor affinity, 26.8 +/- 0.8 (+/- SE) vs 19.8 +/- 0.7 ml kg-1 min-1 for insulin (p less than 0.001), and lowest for the analogue with the lowest receptor affinity, 13.3 +/- 0.8 vs 25.1 +/- 2.0 ml kg-1 min-1 for insulin (p less than 0.001). The apparent plasma half-life was prolonged for the low affinity analogue compared with human insulin (12.6 +/- 0.6 vs 1.9 +/- 0.2 min, p less than 0.001), and significantly shorter for the higher affinity analogue (1.6 +/- 0.1 vs 3.1 +/- 0.4 min, p less than 0.05). The three insulins gave similar falls in blood glucose, non-esterified fatty acids, glycerol, and total ketone bodies over the infusion period. Thirty minutes after the end of the infusion, the rise in blood glucose for the low affinity analogue was significantly less than for human insulin (0.5 +/- 0.2 vs 0.9 +/- 0.1 mmol l-1, p less than 0.05). Despite different receptor affinities, these analogues have similar in vivo effects in normal men, but the time-course of their actions may differ when they are infused intravenously.
Adult↗
Prevalence of haemochromatosis amongst patients with diabetes mellitus.
Four hundred and six white caucasian patients with diabetes mellitus (243 male, mean age 54 +/- 16 (SD) years) were screened for haemochromatosis. Four patients had a fasting transferrin saturation > 62% and all were HLA A3 positive. Two were probable homozygotes for haemochromatosis and two heterozygotes. Homozygote haemochromatosis prevalence in this diabetic population was therefore 2/406 (0.0049) which is identical to that reported in the general population. These findings do not support a genetic relationship between the two conditions.
Adult↗
Basal intermediary metabolism in impaired glucose tolerance and morbid obesity.
The effects of impaired glucose tolerance and obesity, in isolation and in combination, on basal (postabsorptive) intermediary metabolism were examined in four groups of subjects (n = 10 for each) matched for age and gender: Group 1: Non-obese healthy controls with normal glucose tolerance (75 g); Group 2: Non-obese subjects with impaired glucose tolerance; Group 3: Morbidly obese subjects with normal glucose tolerance; Group 4: Morbidly obese subjects with impaired glucose tolerance. While there was no significant difference in fasting blood glucose concentrations between the four groups plasma immuno-reactive insulin concentrations were elevated (p < 0.01 or less) in the obese subjects relative to the non-obese subjects within each category of glucose tolerance. Basal immunoreactive insulin concentrations in non-obese subjects with impaired glucose tolerance were also elevated (p < 0.01) relative to the non-obese healthy controls. Concentrations of glycerol (p < 0.01), non-esterified fatty acids (p < 0.01), and total ketone bodies (p < 0.001) were significantly higher in the obese/normal glucose tolerance and obese/impaired glucose tolerance groups relative to their matched non-obese counterparts. Compared with the subjects with normal glucose tolerance, only lactate (p < 0.05) and pyruvate (p < 0.05) concentrations were elevated in the non-obese/impaired glucose tolerance and obese/impaired glucose tolerance groups, respectively. In conclusion, in addition to fasting hyperinsulinaemia the regulation of lipolysis and ketone body metabolism is abnormal in the basal state in morbid obesity. By contrast, despite normal fasting blood glucose concentrations, impaired glucose tolerance is associated with disturbances of other aspects of basal carbohydrate metabolism.
Adult↗
Detection of glibenclamide in oral insulin capsules.
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Administration, Oral↗
Public awareness of the symptoms of diabetes mellitus.
A cross-sectional survey by standard questionnaire was conducted to determine the public's knowledge (n = 480) of diabetes and diabetes symptoms. Four hundred and sixty-two (96%) subjects had heard of diabetes, 350 (73%) could give a rudimentary definition of diabetes, but 231 (48%) were unable to name any symptom and only 20 (4%) knew of thirst and polyuria in combination. The public's knowledge of diabetes symptoms is poor. This may possibly contribute to delayed presentation of Type 2 diabetes.
Adult↗
Impaired glucose tolerance in obesity is associated with insensitivity to insulin in multiple aspects of metabolism as assessed by a low dose incremental insulin infusion technique.
To determine whether Impaired Glucose Tolerance gives rise to additional defects in insulin action in lipid and ketone metabolism, thirty-two obese subjects were studied by low-dose incremental insulin infusion. Sixteen had Impaired Glucose Tolerance and 16 had normal glucose tolerance. Body mass index was 36.9-80.9 kg m-2 and was similar in each group. In patients with Impaired Glucose Tolerance, plasma insulin was higher in the fasted state (logarithmic mean 14.5 (9.8-21.6) (-SD(-)+SD) vs 9.6 (6.4-14.5) mU l-1, p less than 0.01) and during the infusion (p less than 0.001). The metabolic clearance rate for insulin at the highest infusion rate was lower (14.2 +/- 0.8 (+/- SE) vs 18.9 +/- 2.1 ml kg-1 min-1, p less than 0.05) in these subjects. Basal hepatic glucose production was higher in subjects with Impaired Glucose Tolerance (6.3 +/- 0.4 vs 4.5 +/- 0.6 mol kg-1 min-1, p less than 0.02) and remained elevated during infusion (p less than 0.01). Glucose disposal per unit circulating insulin at the maximal infusion rate was approximately half in subjects with Impaired Glucose Tolerance (0.022 +/- 0.010 vs 0.047 +/- 0.017 ml kg-1 min-1 mU-1 l, p less than 0.01). When simultaneous insulin and metabolite concentrations during the infusion are plotted as dose-response relationships, a difference in relative sensitivity to insulin in Impaired Glucose Tolerance over subjects with normal glucose tolerance is suggested for non-esterified fatty acids 0.72 (95% CI 0.62-0.84) and glycerol 1.85 (1.37-2.49).(ABSTRACT TRUNCATED AT 250 WORDS)
Adolescent↗
A community-based study of diabetes-related skills and knowledge in elderly people with insulin-requiring diabetes.
An open cross-sectional study of elderly (age greater than 65 yr) patients with insulin-requiring diabetes mellitus (n = 57) was undertaken to audit safety of self-management. Levels of knowledge and management skills of hypoglycaemia, hyperglycaemia, and foot care were determined. The prevalence of hypoglycaemia, visual impairment, and at-risk feet and the ability to perform practical procedures (insulin injection and self-monitoring) were assessed. Drawing up insulin and self-injection was correct in 84% and 76% of patients, but 53% of self-monitored urine or blood tests were performed incorrectly. Twenty-six per cent experienced hypoglycaemia at least monthly and 25% had been seen at the hospital with hypoglycaemia in the last year. Eighteen per cent did not know what action to take with hypoglycaemia. Forty-six per cent did not know any hyperglycaemic symptoms or signs. Prompted with symptoms, 35% still did not know what to do and 21% would take inappropriate action when self-monitored tests read high. Fifty-one per cent had impaired vision, 61% peripheral neuropathy and 24% peripheral vascular disease, with the result that 78% had at-risk feet. Fifteen percent inspected or washed their feet infrequently, 40% walked barefoot occasionally, and 47% would take potentially dangerous action in the event of foot injury. This study demonstrates serious deficiencies in the basic education and management skills in our elderly insulin-requiring diabetic population that could result in morbidity and mortality. Greater effort and vigilance by health care professionals must be directed towards this group.
Aged↗
Impaired glucose tolerance is characterized by multiple abnormalities in the regulation of intermediary metabolism.
The responses of circulating intermediary metabolites to a low-dose sequential insulin infusion (basal, 0.005, 0.01, and 0.05 U kg-1 h-1) were assessed in eight non-obese men with Impaired Glucose Tolerance (IGT), and in eight healthy control subjects with normal glucose tolerance matched for age, gender, and body mass index. Fasting hyperinsulinaemia was observed in the subjects with IGT (7.4 +/- 1.0 vs 2.9 +/- 0.3 mU I-1, p less than 0.001). While there was no significant difference (p greater than 0.1) in fasting venous glucose levels between the groups, fasting concentrations of lactate (p less than 0.02), alanine (p less than 0.01), and glycerol (p less than 0.05) were significantly elevated in the subjects with IGT. During the incremental insulin infusion, overall concentrations of glucose (p less than 0.05), lactate (p less than 0.05), alanine (p less than 0.05), glycerol (p less than 0.05), immunoreactive insulin (p less than 0.001), and C-peptide (p less than 0.01) were significantly higher in the subjects with IGT. Linear dose-response relationships (p less than 0.005) for circulating immunoreactive insulin (log) vs metabolite concentrations were demonstrated by analysis of variance for glucose, non-esterified fatty acids (NEFA), glycerol, and total ketone bodies. For glucose, glycerol, and NEFA, group dose-response regression lines for the subjects with IGT were displaced significantly to the right (p less than 0.001 for each) of those for the normal control subjects, implying insulin insensitivity. In addition to the recognized defect in glucose homeostasis, these results indicate impaired regulation of multiple aspects of intermediary metabolism including lipolysis in IGT.
Alanine↗
Effect of obesity on circulating intermediary metabolite concentrations in the absence of impaired glucose tolerance.
The published literature on the influence of obesity on intermediary metabolite concentrations does not adequately address the potential confounding effects of the increased prevalence of impaired glucose tolerance in obese subjects. In order to remove this, we studied 109 subjects with proven normal glucose tolerance ranging from underweight to grossly obese (range 15.3-80.9 body mass index). All had blood intermediary metabolites, plasma insulin and C-peptide measured after an overnight fast. Thirty-six (18 from each end of the range of body mass index) received a 3-hour oral glucose tolerance test for metabolites and insulin. Fasting plasma insulin was highly significantly associated with body mass index (r = 0.72; P less than 0.001). Concentrations of lipid intermediaries were better associated with body mass index than with fasting plasma insulin: non-esterified fatty acids (r = 0.36; P less than 0.001), glycerol (r = 0.47; P less than 0.001) and ketone bodies (r = 0.45; P less than 0.001). Fasting concentrations of carbohydrate intermediaries were, however, better correlated with fasting plasma insulin: lactate (r = 0.29; P less than 0.01), pyruvate (r = 0.24; P less than 0.01) and alanine (r = 0.36; P less than 0.001). Glucose concentrations were associated with both to a similar degree (r = 0.33, r = 0.32, respectively; P less than 0.001). After oral glucose, exaggerated rises in plasma insulin and blood glucose were observed in obese subjects but a lesser rise was seen for lactate. Non-esterified fatty acids and ketones, although having higher fasting concentrations in obese subjects, fell to similar concentrations in the two groups after glucose whereas blood glycerol did not fall so far in the obese subjects. The results suggest, even if those subjects with impaired glucose tolerance are excluded, insensitivity to insulin in several aspects of intermediary metabolism in obesity the degree of which may vary in different metabolic pathways or tissues.
Adult↗
Metabolic abnormalities in obese patients with impaired glucose tolerance.
It is not clear whether the glucose tolerance test diagnosis of Impaired Glucose Tolerance introduced in the recent revisions of diagnostic criteria is associated with abnormalities of intermediary metabolism other than glucose. Intermediary metabolite concentrations have therefore been studied fasting and in response to oral glucose in 35 patients referred with morbid obesity accompanied by either normal glucose tolerance (18 patients) or Impaired Glucose Tolerance (17 patients). When fasting obese patients with Impaired Glucose Tolerance had significantly higher blood total ketone body concentrations, 0.24 (0.19-0.30) vs 0.14 (0.12-0.16) mmol l-1 (antilog of mean-SE to mean + SE) (p less than 0.05), and lower blood glycerol concentrations, 0.14 +/- 0.01 vs 0.18 +/- 0.01 mmol l-1 (mean +/- SE) (p less than 0.05), than obese patients with normal glucose tolerance. There were no significant differences in fasting insulin, 16 (15-18) vs 14 (12-15) mU l-1, or glucose levels, 5.3 +/- 0.2 vs 5.1 +/- 0.2 mmol l-1. After oral glucose there was an exaggerated rise in glucose, insulin, lactate, and pyruvate in patients with Impaired Glucose Tolerance.
Adult↗