Non-insulin-dependent Diabetes Mellitus Group Research Articles

A Comparison Between the Minimal Model and the Glucose Clamp in the Assessment of Insulin Sensitivity Across the Spectrum of Glucose Tolerance

An insulin-modified frequently sampled intravenous glucose tolerance test (FSIGTT) with minimal model analysis was compared with the glucose clamp in 11 subjects with normal glucose tolerance (NGT), 20 with impaired glucose tolerance (IGT), and 24 with non-insulin-dependent diabetes mellitus (NIDDM). The insulin sensitivity index (SI) was calculated from FSIGTT using 22- and 12-sample protocols (SI(22) and SI(12), respectively). Insulin sensitivity from the clamp was expressed as SI(clamp) and SIP(clamp). Minimal model parameters were similar when calculated with SI(22) and SI(12). SI could not be distinguished from 0 in approximately 50% of diabetic patients with either protocol. SI(22) correlated significantly with SI(clamp) in the whole group (r = 0.62), and in the NGT (r = 0.53), IGT (r = 0.48), and NIDDM (r = 0.41) groups (P < 0.05 for each). SI(12) correlated significantly with SI(clamp) in the whole group (r = 0.55, P < 0.001) and in the NGT (r = 0.53, P = 0.046) and IGT (r = 0.58, P = 0.008) but not NIDDM (r = 0.30, P = 0.085) groups. When SI(22), SI(clamp), and SIP(clamp) were expressed in the same units, SI(22) was 66 +/- 5% (mean +/- SE) and 50 +/- 8% lower than SI(clamp) and SIP(clamp), respectively. Thus, minimal model analysis of the insulin-modified FSIGTT provides estimates of insulin sensitivity that correlate significantly with those from the glucose clamp. The correlation was weaker, however, in NIDDM. The insulin-modified FSIGTT can be used as a simple test for assessment of insulin sensitivity in population studies involving nondiabetic subjects. Additional studies are needed before using this test routinely in patients with NIDDM.

Total knee arthroplasty in diabetic patients: Comparison to a matched control group

Between January 1980 and July 1989, 63 total knee arthroplasties were performed on 48 patients who had a clinical history of diabetes mellitus. Six patients died prior to completing the 2-year follow-up period and two patients (3 knees) were lost, leaving 53 knees in 40 patients available for review. The patients were considered as a total group, and were also divided into two subgroups: (1) insulin-dependent diabetes mellitus (IDDM) (9 knees) and (2) noninsulin-dependent diabetes mellitus (NIDDM) (44 knees). There were 10 men and 30 women in the series with an average age of 67. Patients were followed from 24 to 126 months (average, 54 months). The Porous Coated Anatomic total knee system (Howmedica, Rutherford, NJ) was used without cement in 30 knees and with cement in 23 knees. Diabetic patients were matched to a nondiabetic control group using a computer-generated selection process to match the following parameters: (1) age at surgery, (2) sex, (3) arthritic diagnosis, (4) length of follow-up period, (5) mode of fixation, and (6) preoperative deformity. Statistical analysis was performed using regression analysis and chi-square tests. In the diabetic group, there was an average clinical score of 85, with 43 knees (82%) rated excellent or good. Ten knees (18%) were rated fair, poor, or required revision (4 revisions, 7%). This was statistically different from the control group, which had an average clinical score of 92, with 51 knees (96%) rated excellent or good, 1 fair rating, and 1 revision ( P < .001). The results were similar when the IDDM and NIDDM groups were compared (average clinical scores of 84 and 86, respectively) ( P = .6). Of the four revisions in the diabetic group, three involved deep wound infections in cemented total knee arthroplasties. Diabetic patients who have a total knee arthroplasty are at increased risk for a worse final outcome than their nondiabetic counterparts.

Human sciatic nerve phospholipid profiles from non-diabetes mellitus, non-insulin-dependent diabetes mellitus and insulin-dependent diabetes mellitus individuals. A 31P NMR spectroscopy study

1. 1. Human sciatic nerve phospholipids obtained from non-diabetes mellitus (NDM), non-insulin-dependent diabetes mellitus (NIDDM), and insulin-dependent diabetes mellitus (IDDM) patients, after lower extremity amputation, were studied by 31P NMR spectrometry. 2. 2. Nine phospholipids resonances in NDM and NIDDM groups were identified as followed: Ethanolamine plasmalogen (Epias, Chemical shift = 0.07δ); phosphatidylethanolamine (PE, 0.03δ); phosphatidylserine (PS, −0.05δ); sphingomyelin (SM, −0.09δ); lysophosphatidylcholine (LPC, −0.28δ); phosphatidylinositol (PI, −0.30δ); alkylacylphosphorylcholine (A1.PC, -0.78δ); phosphatidylcholine (PC −0.84δ), and an unknown resonance (U, 0.13δ). 3. 3. In the IDDM group a resonance of lysophosphatidylinositol (LPI, 0.01δ) was detected in addition to the nine phospholipids listed above. 4. 4. IDDM showed that PI and Al.PC were elevated and U was lower when compared with NDM; also, Eplas was lower when compared with NIDDM. PC was elevated and PS was lower when compared with both NDM and NIDDM. 5. 5. Indices calculated from this data, showed that the choline ratio and choline/ ethanolamine ratio were elevated; while ethanolamine ratio, and myelin ratio were lower in IDDM group, when compared with both NDM and NIDDM groups. 6. 6. Inactivation of the cholineacethyltransferase enzyme (ChAT) and enhancement of the phospholipidmethyltransferase enzyme (PLMT), secondary to an insulin deficiency, are proposed as an interpretation of these findings.

Platelet volume and urinary prostanoid metabolites in non-insulin-dependent diabetes mellitus.

To evaluate platelet activity in patients with non-insulin-dependent diabetes mellitus (NIDDM), we measured the mean platelet volume (MPV) and 24-hour urinary excretion of 11-dehydro-thromboxane B2 (11-dTXB2) and 6-keto-prostaglandin F1 alpha (6-kPGF1 alpha), stable metabolites of thromboxane A2 and prostacyclin, respectively. The MPV of the 103 subjects in the NIDDM group were 10.72 +/- 0.82 fl for males and 10.52 +/- 1.01 fl for females (mean +/- SD), significantly higher than those of normal controls (9.95 +/- 0.75 fl for males and 9.84 +/- 0.72 fl for females). The MPV of patients with NIDDM showed positive correlations with fasting plasma glucose level and HbA1c (r = 0.234, P < 0.05; r = 0.267, P < 0.01, respectively). The urinary excretion of 11-dTXB2 was greater in the NIDDM group (7.58 +/- 4.42 micrograms/day for males and 5.65 +/- 2.38 micrograms/day for females) than in the normal controls (4.61 +/- 2.31 and 3.83 +/- 1.60, respectively), suggesting that the synthesis of thromboxane A2 by platelets may be accelerated in vivo in patients with NIDDM. The urinary 6-kPGF1 alpha was not different between the NIDDM group and normal controls among the males, but was greater in the NIDDM group among the females. As MPV showed a positive correlation (r = 0.364, P < 0.05) with urinary excretion of 11-dTXB2, MPV may be related to platelet activity. These findings suggest that the platelets of patients with NIDDM may be in a hyperactive state.

Abnormal metabolism of postprandial lipoproteins in patients with non-insulin-dependent diabetes mellitus is not related to coronary artery disease.

To investigate whether abnormalities in alimentary lipemia explain the increased risk of coronary artery disease (CAD) in subjects with non-insulin-dependent diabetes mellitus (NIDDM), we performed an oral vitamin A fat-load test in four groups of men (each n = 15): 1) NIDDM and angiographically verified CAD (DM+CAD+): 2) CAD but no diabetes (DM-CAD+); 3) NIDDM but no CAD, excluded by an exercise thallium scan (DM+CAD-); and 4) healthy control subjects (DM-CAD-). The groups were matched for age and body mass index. Plasma obtained after an overnight fast and 2, 3, 4, 6, 9, 12, and 24 h after a fatty meal (78 g fat, 345,000 IU retinyl palmitate [RP]) was separated by density gradient ultracentrifugation into six fractions of triglyceride (TG)-rich lipoproteins: Svedberg flotation units (Sf) > 3200, Sf 1100-3200, Sf 400-1100, Sf 60-400, Sf 20-60, and Sf 12-20. TG, RP, and cholesterol concentrations were measured in plasma and in each lipoprotein fraction. Postprandial plasma TG responses were significantly larger in both NIDDM groups than in the healthy control group. The most marked differences were observed in the Sf 60-400 lipoproteins, whether measured as TG or RP responses. However, there were no differences between the DM+CAD+ and DM+CAD- groups. The between-group differences in alimentary lipemia were only partially explained by fasting TG levels. In contrast to the healthy subjects, no significant negative correlation was observed in the NIDDM patients between alimentary lipemia and lipoprotein lipase activity, implying an abnormality of the lipolysis of TG-rich particles in NIDDM. Levels of atherogenic postprandial remnant lipoproteins are increased in NIDDM. However, in this study the magnitude of alimentary lipemia did not distinguish NIDDM patients with CAD from those without CAD symptoms and normal exercise thallium scans.

Accelerated cholesteryl ester transfer in noninsulin-dependent diabetes mellitus

Alterations in core lipid composition of lipoproteins in noninsulin-dependent diabetes mellitus (NIDDM) patients have suggested that the heteroexchange of neutral lipids between HDL and the apo B-containing lipoproteins may be enhanced. For this reason, we studied cholesteryl ester transfer (CET) in ten sulfonylurea-treated patients with stable NIDDM. CET measured in all NIDDM subjects with an assay of mass transfer was significantly greater than that of controls at 1 and 2 h ( P < 0.001); the transfer of radiolabeled CE also was increased in a subset of four of the NIDDM group (NIDDM k = 0.21 ± 0.04 vs. control k = 0.10 ± 0.05; P < 0.05). A weak correlation was demonstrable between the mass of CE transferred at 1 h and diabetic control expressed as plasma fructosamine ( r = 0.58, P < 0.09). To characterize this disturbance in CET further, the donor (HDL + VHDL) and acceptor (VLDL + LDL) lipoprotein fractions were isolated by ultracentrifugation at d 1.063 g/ml from NIDDM and control plasma and a series of recombination experiments were performed. Combining NIDDM acceptor with control donor fractions that contained HDL and CETP and not the combination of NIDDM donor and control acceptor lipoproteins resulted in an accelerated CET response identical to that observed in NIDDM whole plasma. This observation indicated that the abnormality in CET in NIDDM was associated with the VLDL + LDL fraction. To discern which lipoprotein class was dysfunctional, VLDL ( d < 1.006 g/ml) and LDL ( d 1.006-1.063 g/ml) from NIDDM and control subjects were isolated and combined with the d > 1.063 g/ml fractions of their respective control at the same triglyceride concentration for VLDL and cholesterol for LDL. These experiments revealed that NIDDM VLDL and not LDL promoted CET. Concentrations of cholesteryl ester transfer protein (CETP) did not differ in the two groups (NIDDM 1.63 ± 0.36 μg/ml vs. control 1.33 ± 0.36). These findings indicate that CET is increased in the plasma of NIDDM patients, and this abnormality appears to result from dysfunction of VLDL. Since this abnormality may promote the generation of increased numbers of potentially atherogenic cholesteryl ester-enriched apo B-containing lipoproteins, it may be a previously unrecognized risk factor that contributes to the development of macrovascular complications in NIDDM.

Selective impairment of the cytoplasmic Ca 2+ response to glucose in pancreatic β cells of streptozocin-induced non-insulin-dependent diabetic rats

Pancreatic islets from the streptozocin-induced non-insulin-dependent diabetes mellitus (NIDDM) rat model showed a diminished insulin response to 16.7 mmol/L glucose, but the insulin response to arginine remained intact. To evaluate the importance of intracellular calcium concentration ([Ca 2+] i) in the diminished insulin response to glucose, the [Ca 2+] i of pancreatic β cells was investigated using fura-2. Glucose produced heterogeneous responses of [Ca 2+] i, which were in β-cell clusters of both the control and NIDDM groups. Many cells showed initial slight decreases of [Ca 2+] i, which were followed by gradual and large increments of [Ca 2+] i after glucose stimulation of β cells in the control group. On the other hand, the increase of [Ca 2+] i in response to glucose was markedly diminished in β cells of the NIDDM group compared with controls. The average lag time to [Ca 2+] i elevation of β cells in the NIDDM group was significantly longer than that of the control group. Arginine produced marked increases of [Ca 2+] i, in contrast to the effect of glucose stimulation in the NIDDM group. These results suggest that the diminished and delayed [Ca 2+] i increases in β cells of NIDDM rats in response to glucose stimulation are responsible for the selectively impaired insulin response to glucose in the rat model of NIDDM.

Lack of control by glucose of ultradian insulin secretory oscillations in impaired glucose tolerance and in non-insulin-dependent diabetes mellitus.

Normal subjects demonstrate the presence of ultradian oscillations (period 80-150 min) in insulin secretion rate (ISR) tightly coupled to glucose oscillations of similar period. These oscillations appear to be a function of the feedback loop linking glucose and insulin. The present study was undertaken to determine whether the control by glucose of the ultradian oscillations in insulin secretion is altered in impaired glucose tolerance IGT and in non-insulin-dependent diabetes mellitus (NIDDM). Patients with NIDDM (n = 7), IGT (n = 4), and matched nondiabetic controls (n = 5) were studied under three separate protocols that involved administration of glucose at either a constant rate of 6 mg/kg per min for 28 h or in one of two oscillatory patterns at the same overall mean rate. The amplitude of the oscillations was 33% above and below the mean infusion rate, and their respective periods were 144 min (slow oscillatory infusion) or 96 min (rapid oscillatory infusion). Insulin, C-peptide, and glucose were sampled at 10-min intervals during the last 24 h of each study. ISRs were calculated by deconvolution of C-peptide levels. Analysis of the data showed that (a) the tight temporal coupling between glucose and ISR in the nondiabetic controls was impaired in the IGT and NIDDM groups as demonstrated by pulse analysis, cross-correlation analysis, and spectral analysis; (b) the absolute amplitude of the ISR pulses progressively declined with the transition from obesity to IGT to NIDDM; and (c) the absolute amplitude of the ISR oscillations failed to increase appropriately with increasing absolute amplitude of glucose oscillations in the IGT and NIDDM subjects compared with the control group. In conclusion, the present study demonstrates that important dynamic properties of the feedback loop linking insulin secretion and glucose are disrupted not only in established NIDDM but also in conditions where glucose tolerance is only minimally impaired. Further studies are needed to determine how early in the course of beta-cell dysfunction this lack of control by glucose of the ultradian oscillations in insulin secretion occurs and to define more precisely if this phenomenon plays a pathogenetic role in the onset of hyperglycemia in genetically susceptible individuals.

Expression of the major insulin regulatable glucose transporter (GLUT4) in skeletal muscle of noninsulin-dependent diabetic patients and healthy subjects before and after insulin infusion.

In a cross-sectional study we have examined the regulatory effect of insulin in vivo on the major insulin regulatable glucose transporter (GLUT4) in vastus lateralis muscle from 12 noninsulin-dependent diabetes mellitus (NIDDM) patients and 8 healthy control subjects. Insulin-stimulated glucose uptake rate in peripheral tissue was decreased by 41% (P < 0.01) in NIDDM patients compared to healthy subjects, whereas no significant differences could be shown in the abundance of total GLUT4 protein per DNA or GLUT4 messenger RNA (mRNA) per DNA among the 2 groups in muscle biopsies obtained in the basal state. In healthy subjects, 4 h of insulin infusion (2 mU/kg/min) induced a 31% reduction (P < 0.05) in the total GLUT4 protein content per DNA and a 35% increase (P < 0.05) in GLUT4 mRNA per DNA, whereas the GLUT4 mRNA and protein responses to insulin were heterogenous and statistically unaltered in the NIDDM patients. The GLUT4 protein per DNA of muscle obtained in the basal state correlated positively with the in vivo insulin-stimulated glucose uptake rate in the control group (r = 0.82, P < 0.05), whereas there was no comparable correlation in the NIDDM group (r = 0.05, P = 0.88). Furthermore, GLUT4 protein content in skeletal muscle after 4 h of insulin infusion did not correlate with insulin-stimulated glucose uptake in any of the groups. In conclusion, 4 h of insulin infusion causing supraphysiological serum insulin levels modulates the expression of GLUT4 in skeletal muscle from healthy subjects, with divergent effects at protein and mRNA levels. The physiological significance of these observations will have to be elucidated in future studies. Factors other than total GLUT4 protein content of muscle play a role in determining insulin-stimulated glucose uptake in human skeletal muscle.

Renal handling of insulin and C-peptide in patients with non-insulin-dependent diabetes mellitus

The kidney is responsible for a considerable part of the clearance of insulin and C-peptide. Two routes are thought to be involved in the renal extraction of insulin and C-peptide from the circulation: (1) glomerular filtration, and (2) uptake by tubular cells from peritubular capillaries. The aim of the present study was to investigate these processes in non-insulin-dependent diabetes mellitus (NIDDM). For this purpose we measured the renal extraction of inulin, insulin, and C-peptide in 12 NIDDM patients and 16 control subjects during elective heart catheterization. In addition, a 24-h urine sample was obtained from all subjects to assess the fractional clearance of the peptides. The total renal extraction of both insulin and C-peptide exceeded the amount that was extracted by filtration, confirming the supposition that both peptides are cleared by an additional mechanism, most probably peritubular uptake. The peritubular uptake of insulin in the NIDDM group was not significantly different from that in the control subjects, whereas the insulin extraction over the legs was significantly lower in NIDDM than in the controls. The peritubular uptake of C-peptide was significantly lower in NIDDM, while the fractional clearance of C-peptide was significantly higher. The latter indicates that the reabsorption of C-peptide from the luminal side of the tubular cell is impaired in diabetes mellitus. It is therefore concluded that urinary C-peptide excretion is not a reliable index for insulin production in NIDDM.(ABSTRACT TRUNCATED AT 250 WORDS)

Oral health and salivary composition in diabetic patients

The salivary composition and flow rate were examined in 20 patients with insulin-dependent diabetes mellitus (IDDM) and in 19 patients with non-insulin-dependent diabetes mellitus (NIDDM) and compared with 20 healthy controls. Resting and stimulated whole and submandibular saliva was analyzed. Significantly lower resting salivary flow rates were found in the IDDM patients as compared to the NIDDM group. In the IDDM patients potassium concentration in resting saliva was significantly higher compared with healthy controls and in stimulated whole saliva compared with NIDDM patients. No difference in salivary total protein, amylase, lactoferrin, or lysozyme was found among the three groups examined. The IgA concentration of the IDDM patients was significantly higher in whole resting saliva compared with controls and in the submandibular saliva compared with both NIDDM patients and controls. No difference was found between controls and the diabetic patients examined in prevalence of complaint of dry mouth. The salivary flow rates, however, were significantly lower in the three subgroups with dry mouth compared with the subgroups without this complaint. Caries were detected in 100% of the diabetic patients and controls. No correlation was observed between the incidence of caries and any of the salivary parameters examined. A higher prevalence and severity of periodontal disease was detected in the diabetic patients as compared to the controls. A significant positive correlation was found between the gingival index and the concentrations of total protein, albumin, lysozyme, and lactoferrin in whole resting saliva in the three groups examined.

Impact of diabetic status, dietary intake, physical activity, and smoking status on body mass index in NHANES II

Individuals with non-insulin-dependent diabetes mellitus (NIDDM) have a higher body mass index (BMI) than nondiabetic individuals and it has been reported that individuals with NIDDM have more difficulty losing excess weight. To assess an independent effect of NIDDM on weight status, analyses were conducted to predict BMI with variables previously associated with weight status. Subjects from the Second National Health and Nutrition Examination Survey were categorized into three groups: individuals with NIDDM and on oral medication, individuals with diet-controlled NIDDM, and nondiabetic adults. Additionally, planned orthogonal comparisons between these groups were conducted after other predictors were controlled for; 9.18% of the variability was explained for men (P less than 0.001) whereas 12.11% was explained for women (P less than 0.0001), with several variables significantly related in each model. An independent effect for diabetes status was found in both sexes and there were no differences in BMI between NIDDM groups in either sex.

Estimation of plasma glucose fluctuation with a combination test of hemoglobin A 1c and 1,5-anhydroglucitol

We investigated the effect of plasma glucose fluctuation on hemoglobin A 1c (HbA 1c) and plasma 1,5-anhydroglucitol (AG) levels, especially in insulin-dependent diabetes mellitus (IDDM). Plasma AG is a new marker that provides sensitive and analytical information on glycemic control. The basic mechanisms underlying both the reduction and recovery of the plasma AG level, ie, the excretion into urine with glucosuria and the amount supplied to the body, were presumed to be similar in IDDM and non-insulin-dependent diabetes mellitus (NIDDM) patients. The correlation coefficient for mean plasma glucose and AG was −.591, and it was .578 for mean plasma glucose and HbA 1c in IDDM patients. In NIDDM, the correlation between mean plasma glucose and AG was −.869, and between mean plasma glucose and HbA 1c, .875. The plasma AG levels in the IDDM group showed a lower range than in the NIDDM group, even with similar HbA 1c levels. All the cases showing lower plasma AG levels among those with similar HbA 1c levels manifested greater fluctuation of plasma glucose and a larger amount of urinary glucose. The lower AG level in IDDM patients was reversible to the level in NIDDM patients when the greater fluctuation of plasma glucose was corrected. Thus, it was suggested that because urinary glucose excretion is intermittently high in IDDM patients, plasma AG is frequently low, even though the mean plasma glucose and HbA 1c levels suggest good control. The results of the present study indicate the significance of both plasma glucose fluctuation and mean plasma glucose level for an evaluation of glycemic control, especially in IDDM patients, and imply the danger of frequent hypoglycemia if the improvement of glycemic control is evaluated by HbA 1c alone.

Impaired glucose sensitivity of ATP-sensitive K+ channels in pancreatic beta-cells in streptozotocin-induced NIDDM rats.

ATP-sensitive K+ channels (KATP channels) are known to play a key role in the cellular mechanism of insulin secretion from pancreatic beta cells. In order to examine the possible impairment of KATP channel function in non-insulin-dependent diabetes mellitus (NIDDM), we have studied the properties of the KATP channels in single beta cells of neonatally streptozotocin-induced diabetic rats (NSZ rats) using the patch-clamp technique. The unitary conductance of the channel in diabetic beta-cells was virtually identical to that in control beta cells and there was no difference in the sensitivity to ATP and glibenclamide of KATP channels between the NIDDM and control groups. In response to glucose, the activity of the KATP channels was diminished in a dose-dependent manner in both control and diabetic cells. However, the inhibition of the KATP channels in beta-cells of NSZ rats was significantly less than that in control cells. Even in the presence of 11.1 mM glucose, the openings of a few single KATP channels were consistently observed in cell-attached patch membranes of diabetic, but not control, beta-cells. Thus, it appears that the impaired insulinotropic action of glucose in beta-cells in NSZ rats is associated with a reduced sensitivity of the KATP channel to glucose, but not to ATP, presumably due to a deficiency in glucose metabolism.

Intracellular defects in glucose metabolism in obese patients with NIDDM.

Skeletal muscle insulin resistance in obese patients with non-insulin-dependent diabetes mellitus (NIDDM) is characterized by decreased glucose uptake. Although reduced glycogen synthesis is thought to be the predominant cause for this deficit, studies supporting this notion often have been conducted at supraphysiological insulin concentrations in which glucose storage is the overwhelming pathway of glucose disposal. However, at lower, more physiological insulin concentrations, decreased muscle glucose oxidation could play a significant role. This study was undertaken to determine whether, under euglycemic conditions, insulin resistance for leg muscle glucose uptake in NIDDM patients is due primarily to decreased glucose storage or to oxidation. The leg balance technique and leg indirect calorimetry were used under steady-state euglycemic conditions to estimate muscle glucose uptake, storage, and oxidation in eight moderately obese NIDDM patients and eight matched-control subjects. Leg muscle biopsies also were performed to determine whether alterations in muscle pyruvate dehydrogenase or glycogen synthase activities could explain defects in glucose oxidation or storage. At insulin concentrations of approximately 500-600 pM, leg glucose uptake, oxidation, and storage in the NIDDM group (2.03 +/- 0.42, 1.00 +/- 0.13, 0.66 +/- 0.36 mumol.min-1.100 ml-1) were significantly lower (P less than 0.05) than rates in control subjects (5.14 +/- 0.64, 1.92 +/- 0.17, 2.80 +/- 0.54). Pyruvate dehydrogenase and glycogen synthase activities were also decreased, consistent with the in vivo metabolic defects. The average deficit in leg glucose uptake in NIDDM was 3.11 +/- 0.42 mumol.min-1.100 ml-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology of Hypertension in Diabetic Patients and Implications for Treatment

We review the epidemiology of hypertension in diabetic patients and discuss the implications for treatment. The relationship between coronary heart disease (CHD) mortality and blood pressure (BP) in the World Health Organization Multinational Study of Vascular Disease in Diabetics (WHO MSVDD) is evaluated. One thousand two hundred seventy-seven patients with insulin-dependent diabetes mellitus (IDDM) and 3463 patients with non-insulin-dependent diabetes mellitus (NIDDM), aged 35-55 yr at baseline, from 10 centers throughout the world were evaluated. CHD mortality after a follow-up of 6-7 yr was measured. Estimates of usual diastolic BP were made with data from the Framingham study. The relative risk (RR) of CHD death was plotted against usual diastolic BP for IDDM and NIDDM, and the shapes of the relationship were compared with a meta-analysis of nine prospective studies in nondiabetic populations. For the NIDDM group, the CHD RRs were significantly greater than 1.0 only for the uppermost diastolic BP category (RR 2.23, 95% confidence interval 1.14-4.40). For the IDDM group, the shape of the diastolic BP-CHD relationship was difficult to assess in view of the small number of events. In neither diabetic group was the evidence for a J-shaped relationship. Elevated BP is associated with increased cardiovascular/renal mortality in both types of diabetes. However, the efficacy of antihypertensive therapy in the prevention of these outcomes remains unclear. Prospective data from the WHO MSVDD do not provide clear evidence of benefit from treating diastolic BP less than 95-100 mmHg in NIDDM patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased expression of glucose transporter in muscle from insulin-resistant patients

We have observed that in vitro incubated human muscle fiber strips from obese patients with or without non-insulin-dependent diabetes mellitus (NIDDM) have reduced insulin-stimulated glucose transport rates compared with nonobese control patients. To investigate if the decrease in glucose transport is associated with a depletion of glucose transport protein, we performed Western blot analysis of muscle samples from nonobese control, obese nondiabetic, and obese NIDDM patients to measure the levels of the muscle-adipose tissue glucose transporter (GLUT-4) protein. Glucose transporter protein was depressed by 23% in the obese nondiabetic and 18% in the obese NIDDM group. The results were essentially the same in the rectus abdominus and vastus lateralis muscles. These data suggest that the decreased glucose transport rate observed in muscle of these obese patients with or without NIDDM may be due, at least in part, to a decreased expression of the "insulin-sensitive" (GLUT-4) glucose transporter. This alteration may play a role in the insulin resistance seen in obesity and diabetes.

Influence of Obesity, Impaired Glucose Tolerance, and NIDDM on LDL Structure and Composition: Possible Link Between Hyperinsulinemia and Atherosclerosis

The possible causes of the enhanced risk for coronary heart disease (CHD) were examined in morbidly obese women with normoglycemia, impaired glucose tolerance (IGT), and non-insulin-dependent diabetes mellitus (NIDDM) before and after gastric bypass surgery. Compared with age-matched lean women, plasma lipid and apolipoprotein concentrations of the obese women before surgery favored atherogenesis. The risk for CHD may further be exacerbated in the IGT and NIDDM groups by the prevalence of smaller and denser low-density-lipoprotein (LDL) particles. LDL size correlated negatively with plasma insulin levels independent of triglyceride levels, age, or body mass index (BMI). After surgery, BMI, plasma insulin, and triglyceride levels decreased, but LDL size increased, and LDL density decreased. Neither cholesterol nor LDL cholesterol levels were affected after surgery, but high-density-lipoprotein cholesterol was increased in all patients after surgery. Although the mechanisms underlying the changes in the properties of LDL could not be determined from this study, these changes appear to be of benefit in reducing CHD risk in these patients.

Age of onset and type of Japanese younger diabetics in Tokyo

The age of onset of diabetes and the type of diabetes were examined in 1408 Japanese patients who were initially diagnosed as having diabetes under the age of 30 and were registered in our Diabetes Center between 1980 and 1989. Of the 1408 patients, 538 (38.2%) had insulin-dependent diabetes mellitus (IDDM) (male/female ratio of 2:3), and 870 (61.8%) had non-insulin-dependent diabetes mellitus (NIDDM) (male/female ratio of 5:4). There were significant differences of the sex ratio in both IDDM and NIDDM. The age at which the numbers in both the IDDM and NIDDM groups were almost equal was 13–14 (26 for IDDM and 23 for NIDDM at 13; 28 for IDDM and 30 for NIDDM at 14). A total of 58% of IDDM patients (22% of all patients) and only 6% of NIDDM patients (4% of all patients) were diagnosed under the age of 14 ( P < 0.01). Of the patients with IDDM, 42% (16% of all patients) were diagnosed over the age of 14, as were 94% of NIDDM (58% of all patients). The percentage of NIDDM cases increased even more over the age of 28, and no NIDDM patients developed diabetes under the age of 9.

Corneal autofluorescence in diabetic and penetrating keratoplasty patients as measured by fluorophotometry

At first it was verified that the major part of the fluorophotometer signal obtained when measuring corneal autofluorescence originated from fluorescence and not from scatter of excitation light at the corneal surface. The minimum percentage of the signal which can be attributed to fluorescence was determined using a fluorescence blocking filter placed in the excitation and fluorescence light path, respectively. The minimum percentages in two healthy controls, two diabetic patients and two patients after penetrating keratoplasty ranged from 75% to 93% (mean 84%). Then the corneal autofluorescence was determined in 22 healthy controls, 18 non-insulin-dependent diabetes mellitus (NIDDM), 23 insulin-dependent diabetes mellitus (IDDM) and 21 penetrating keratoplasty patients in order to detect a possible difference in autofluorescence as a result of diabetes or penetrating keratoplasty. The means of the corneal peak autofluorescence values in the NIDDM, IDDM and penetrating keratoplasty patient groups were significantly higher than that in the healthy control group (mean values in ng equivalent fluorescein ml −1: 18·0±4·2 s.d., 20·6±5·1 s.d., 17·9±5·5 s.d. and 13·7±3·7 s.d., respectively; P < 0·01). The mean values in the NIDDM and IDDM patients did not differ significantly ( P = 0·09). The autofluorescence values were independent of age in all four groups (linear correlation coefficient: r < 0·47). The corneal peak autofluorescence was linearly correlated with the diabetes duration in the NIDDM and IDDM patients [ r = 0·6, P = 0·02; increase: 0·36 ng equiv. fluorescein ml −1 yr diabetes −1]. Our results show that corneal autofluorescence is an easily obtained parameter which can be of assistance in evaluating corneal metabolism.