Phenotyping animal models of diabetic neuropathy: a consensus statement of the diabetic neuropathy study group of the EASD (Neurodiab).

NIDDK, JDRF, and the Diabetic Neuropathy Study Group of EASD sponsored a meeting to explore the current status of animal models of diabetic peripheral neuropathy. The goal of the workshop was to develop a set of consensus criteria for the phenotyping of rodent models of diabetic neuropathy. The discussion was divided into five areas: (1) status of commonly used rodent models of diabetes, (2) nerve structure, (3) electrophysiological assessments of nerve function, (4) behavioral assessments of nerve function, and (5) the role of biomarkers in disease phenotyping. Participants discussed the current understanding of each area, gold standards (if applicable) for assessments of function, improvements of existing techniques, and utility of known and exploratory biomarkers. The research opportunities in each area were outlined, providing a possible roadmap for future studies. The meeting concluded with a discussion on the merits and limitations of a unified approach to phenotyping rodent models of diabetic neuropathy and a consensus formed on the definition of the minimum criteria required for establishing the presence of the disease. A neuropathy phenotype in rodents was defined as the presence of statistically different values between diabetic and control animals in 2 of 3 assessments (nocifensive behavior, nerve conduction velocities, or nerve structure). The participants propose that this framework would allow different research groups to compare and share data, with an emphasis on data targeted toward the therapeutic efficacy of drug interventions.

Painful diabetic peripheral neuropathy: consensus recommendations on diagnosis, assessment and management.

Painful diabetic peripheral neuropathy (DPN) is common, is associated with significant reduction in quality of life and poses major treatment challenges to the practising physician. Although poor glucose control and cardiovascular risk factors have been proven to contribute to the aetiology of DPN, risk factors specific for painful DPN remain unknown. A number of instruments have been tested to assess the character, intensity and impact of painful DPN on quality of life, activities of daily living and mood. Management of the patient with DPN must be tailored to individual requirements, taking into consideration the co-morbidities and other factors. Pharmacological agents with proven efficacy for painful DPN include tricyclic anti-depressants, the selective serotonin and noradrenaline re-uptake inhibitors, anti-convulsants, opiates, membrane stabilizers, the anti-oxidant alpha-lipoic acid and topical agents including capsaicin. Current first-line therapies for painful DPN include tricyclic anti-depressants, the serotonin and noradrenaline re-uptake inhibitor duloxetine and the anti-convulsants pregabalin and gabapentin. When prescribing any of these agents, other co-morbidities and costs must be taken into account. Second-line approaches include the use of opiates such as synthetic opioid tramadol, morphine and oxycodone-controlled release. There is a limited literature with regard to combination treatment. In extreme cases of painful DPN unresponsive to pharmacotherapy, occasional use of electrical spinal cord stimulation might be indicated. There are a number of unmet needs in the therapeutic management of painful DPN. These include the need for randomized controlled trials with active comparators and data on the long-term efficacy of agents used, as most trials have lasted for less than 6 months. Finally, there is a need for appropriately designed studies to investigate non-pharmacological approaches.

Autonomic imbalance: prophet of doom or scope for hope?

It has long been recognized that cardiac autonomic neuropathy increases morbidity and mortality in diabetes and may have greater predictive power than traditional risk factors for cardiovascular events. Significant morbidity and mortality can now be attributable to autonomic imbalance between the sympathetic and parasympathetic nervous system regulation of cardiovascular function. New and emerging syndromes include orthostatic tachycardia, orthostatic bradycardia and an inability to use heart rate as a guide to exercise intensity because of the resting tachycardia. Recent studies have shown that autonomic imbalance may be a predictor of risk of sudden death with intensification of glycaemic control. This review examines an association of autonomic dysregulation and the role of inflammatory cytokines and adipocytokines that promote cardiovascular risk. In addition, conditions of autonomic imbalance associated with cardiovascular risk are discussed. Potential treatment for restoration of autonomic balance is outlined.

The efficacy of pregabalin for treating pain associated with diabetic peripheral neuropathy in subjects with type 1 or type 2 diabetes mellitus.

OBJECTIVE: The objective of this study was to compare the efficacy and safety of pregabalin for painful diabetic peripheral neuropathy (pDPN) in subjects with type 1 (T1DM) or 2 diabetes mellitus (T2DM). METHODS: Pooled data from 10 randomized clinical trials (pregabalin-treated T1DM and T2DM subjects with pDPN) were analyzed for change from baseline (CFB) scores (pain and sleep disturbance) using mixed model repeated measures (MMRM) through Week 12 and last observation carried forward (LOCF). Adverse events (AEs) were recorded. RESULTS: Pregabalin-treated (T1DM 156 [8.7%]; T2DM 1632 [91.3%]) and placebo subjects (T1DM 92 [9.6%]; T2DM 868 [90.4%]) had comparable baseline demographic characteristics between treatment groups within the same diabetes type. T2DM (vs. T1DM) subjects were ∼10 years older. With pregabalin and placebo, respectively, mean ± SD baseline pain (T1DM: 6.2 ± 1.4 and 6.5 ± 1.6; T2DM: 6.5 ± 1.5 and 6.4 ± 1.5) and sleep scores (T1DM: 5.2 ± 2.4 and 5.2 ± 2.7; T2DM: 5.3 ± 2.5 and 5.1 ± 2.5) were comparable. Using MMRM, mean CFB treatment differences (pregabalin minus placebo) were significantly different for pain and sleep with either diabetes types (all weeks p < .05). With LOCF, pregabalin's odds ratios (ORs) of achieving 30% pain reduction were similar with T2DM (OR, 1.91, 95% CI [1.61, 2.27]) and T1DM (2.01 [1.18, 3.44]) (both p ≤ .01). Pregabalin's ORs of 30% improvement in sleep quality were 1.81 (95% CI, 1.06, 3.09) with T1DM and 2.01 (1.69, 2.39) with T2DM (both p < .05). AEs were consistent with the known safety profile of pregabalin. CONCLUSIONS: Pregabalin significantly improved pain and sleep quality, without a clinically meaningful difference between diabetes types. ClinicalTrial.gov registration: NCT00156078, NCT00159679, NCT00143156, NCT00553475.

Action of gastrin in guinea pig oxyntic cells. Studies using quantitative cytochemistry.

The mechanism of action of gastrin was investigated using cytochemical quantitation of hydroxyl ion production (HIP) in guinea pig gastric oxyntic mucosa. The reaction depends upon the trapping of OH ions produced during gastric stimulation and is blocked by the benzimidazole, Hassle 149/94, which inhibits the K+ + H+-ATPase and by acetazolamide, an inhibitor of carbonic anhydrase activity. It is thus a measure of hydroxyl ions produced during stimulation of the oxyntic cell and reflects upon hydrogen ion production. Gastrin (2.5 X 10(-16) -2.5 X 10(-12) M) caused a linear dose-dependent stimulation of HIP in the oxyntic cells. The response was biphasic, with an early peak at 90 s and a secondary rise at 240 s, which persisted for 10 min. Natural human gastrin (sulfated and nonsulfated) and the active COOH-terminal octapeptide fragment of gastrin stimulated HIP, whereas the biologically inert NH2-terminal (1-13) fragment of gastrin had no effect. The activation of oxyntic cell HIP by gastrin was neutralized by an antiserum directed towards the COOH-terminus of gastrin and not by nonimmune serum. Cimetidine (10(-5) M) blocked 25% and atropine (10(-5) M) had no effect on gastrin-stimulated HIP. EGTA (10(-3) M) and LaCl3 (10(-3) M) inhibited the action of gastrin by 67 and 52%, respectively. The calmodulin antagonists, trifluoperazine (10(-5) M), pimozide (10(-5) M), and the naphthalene sulfonamides, W-7 and W-13 (10(-5) M), inhibited gastrin-stimulated HIP by 45.6 38.5, 42.3, and 37.2%, respectively. Higher doses of W-7 and W-13 (10(-4) M) inhibited gastrin-stimulated HIP by 83 and 67%. The Ca2+ ionophore, A23187 (10(-4) M), stimulated HIP. Thus, it appears that gastrin stimulation of HIP is complex. 25% of its action is via a histamine-dependent pathway. 45% of its action is dependent upon extracellular Ca2+. Its action is also in part dependent upon a Ca2+/calmodulin mechanism.

Cloning and sequencing of the pancreatic islet neogenesis associated protein (INGAP) gene and its expression in islet neogenesis in hamsters.

Induction of islet neogenesis by cellophane wrapping (CW) reverses streptozotocin-induced (STZ) diabetes. Administration of Ilotropin, a protein extract isolated from CW pancreata, causes recapitulation of normal islet ontogeny and reverses STZ diabetes, reducing mortality by 50%. We investigated the hypothesis that a novel gene encoding a constituent of Ilotropin was expressed in the hamster pancreas undergoing islet neogenesis. Islet neogenesis associated protein (INGAP) is a product of a novel gene expressed in regenerating hamster pancreas. Northern blot analysis showed a strong single transcript of 850 bp at 1 and 2 d after CW that disappeared by the 6th day and was absent from untreated control pancreata. INGAP gene is expressed in acinar cells, but not in islets. Western blot analysis demonstrated the presence of INGAP in Ilotropin but not in extracts from control pancreata. A synthetic pentadecapeptide, corresponding to a region unique to INGAP, stimulated a 2.4-fold increase in [3H]thymidine incorporation into hamster duct epithelium in primary culture and a rat pancreatic duct cell line but had no effect on a hamster insulinoma tumor cell line. A portion of human INGAP gene was cloned and appears to be highly homologous to the hamster gene. This data suggests that the INGAP gene is a novel pancreatic gene expressed during islet neogenesis whose protein product is a constituent of Ilotropin and is capable of initiating duct cell proliferation, a prerequisite for islet neogenesis.

Treatment of gastroparesis: a multidisciplinary clinical review.

This clinical review on the treatment of patients with gastroparesis is a consensus document developed by the American Motility Society Task Force on Gastroparesis. It is a multidisciplinary effort with input from gastroenterologists and other specialists who are involved in the care of patients with gastroparesis. To provide practical guidelines for treatment, this document covers results of published research studies in the literature and areas developed by consensus agreement where clinical research trials remain lacking in the field of gastroparesis.

Alternative Quantitative Tools in the Assessment of Diabetic Peripheral and Autonomic Neuropathy.

Here we review some seldom-discussed presentations of diabetic neuropathy, including large fiber dysfunction and peripheral autonomic dysfunction, emphasizing the impact of sympathetic/parasympathetic imbalance. Diabetic neuropathy is the most common complication of diabetes and contributes additional risks in the aging adult. Loss of sensory perception, loss of muscle strength, and ataxia or incoordination lead to a risk of falling that is 17-fold greater in the older diabetic compared to their young nondiabetic counterparts. A fall is accompanied by lacerations, tears, fractures, and worst of all, traumatic brain injury, from which more than 60% do not recover. Autonomic neuropathy has been hailed as the "Prophet of Doom" for good reason. It is conducive to increased risk of myocardial infarction and sudden death. An imbalance in the autonomic nervous system occurs early in the evolution of diabetes, at a stage when active intervention can abrogate the otherwise relentless progression. In addition to hypotension, many newly recognized syndromes can be attributed to cardiac autonomic neuropathy such as orthostatic tachycardia and bradycardia. Ultimately, this constellation of features of neuropathy conspire to impede activities of daily living, especially in the patient with pain, anxiety, depression, and sleep disorders. The resulting reduction in quality of life may worsen prognosis and should be routinely evaluated and addressed. Early neuropathy detection can only be achieved by assessment of both large and small- nerve fibers. New noninvasive sudomotor function technologies may play an increasing role in identifying early peripheral and autonomic neuropathy, allowing rapid intervention and potentially reversal of small-fiber loss.

Low molecular weight GTP-binding proteins are altered in platelet hyperaggregation in IDDM.

We examined the hypothesis that hyperaggregating platelets from patients with insulin dependent diabetes mellitus (IDDM) have an alteration in location and function of the guanine nucleotide (GTP)-binding proteins. Platelets from 10 IDDM and 12 age-matched healthy control subjects were collected and washed. Thrombin-induced platelet aggregation (0.025 and 0.05 units for 60 seconds) was increased in IDDM (8.3 +/- 1.8% vs 22.3 +/- 4.4%, P < .05 and 49.9 +/- 7.3% vs 70.9 +/- 7.0%, P < .05). Four small molecular weight GTP-binding proteins were identified by binding of [32P]-GTP on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the cytosol and membranes of these platelets. Each showed specificity for binding [32P]-GTP by competitive inhibition with unlabeled GTP. The total of the 27/28 kDa proteins was decreased in the membrane fraction (414 +/- 30 vs 252 +/- 40 dpm micrograms-1 protein x min, P < .05) and increased in the cytosolic fraction (62 +/- 8 vs 129 +/- 21 dpm unit-1 LDH x min, P < .05) in IDDM. The 21 kDa protein (60.3 +/- 3.5 vs 45.4 +/- 2.9 dpm micrograms-1 protein x min, P < .05) was decreased in platelet membrane in persons with IDDM. In conclusion, increased platelet aggregation in IDDM is accompanied by an altered cellular distribution of a 27/28 kDa GTP-binding protein. These data suggest that the low molecular weight GTP-binding proteins of the 27/28 kDa range may play an important regulatory role in the hyperaggregatory platelets in diabetes.

Induction of nesidioblastosis will reverse diabetes in Syrian golden hamster.

Nesidioblastosis, which is the formation of new islets and the differentiation of cells within the islets, represents part of the spectrum of hyperfunctioning states of the islets of Langerhans at the clinical level. Nesidioblastosis in the Syrian golden hamster can be induced by wrapping the head of the pancreas with cellophane tape. Ligation of the duct is not involved, and acinar cell atrophy does not occur. The purpose of this study was to determine whether the induction of nesidioblastosis could be used as a means of reversing streptozocin-induced diabetes. Outbred hamsters (n = 32), 8 wk of age, were rendered diabetic by treatment with 40 mg/kg i.p. streptozocin, administered daily for 3 days. Four days later, 16 animals chosen at random underwent laparotomy with cellophane wrapping of the pancreas. Before surgery, the serum glucose and insulin levels (means +/- SE) in the unoperated control animals (389.0 +/- 18.6, 33.9 +/- 3.8) did not differ from those in the animals awaiting the operation (373.2 +/- 18.6, 37.9 +/- 3.8). After 7 wk, 50% of the operated animals had serum glucose and insulin levels that were normal, compared to only 12% of the unoperated control animals (chi2 = 5.53, P less than .05). Islets from normoglycemic operated animals were characterized by increased numbers, including many small islets, positive immunoreactive insulin staining, and minimal vacuolation of cells. Islets from hyperglycemic operated hamsters and from the unoperated control animals were decreased in number and generally larger in size, demonstrated little or no immunoreactive insulin staining, and exhibited marked vacuolation of cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased platelet phosphoinositide turnover and enhanced platelet activation in IDDM.

Individuals with diabetes mellitus may have increased in vivo platelet activity. Abnormal platelet function could contribute to the increased incidence of vascular disease in diabetes mellitus. The biochemical mechanism(s) for platelet hyperactivation is unknown. We examined the hypothesis that platelet phosphoinositide turnover, a key signal-transducing mechanism involved in platelet activation, was abnormal in diabetic subjects. Platelets were harvested from 16 subjects with insulin-dependent diabetes mellitus (IDDM) and 19 healthy, nondiabetic control subjects of comparable age. Plasma beta-thromboglobulin (beta-TBG), a specific marker of platelet activity in vivo, was increased in IDDM (67.1 +/- 7.3 ng/ml) compared with control (41.0 +/- 6.0 ng/ml) subjects (P less than .005). [32P]orthophosphate (32Pi) incorporation into the individual phosphoinositides and phosphatidic acid (PA) reached isotopic equilibrium by 120 min for IDDM and control subjects. Specific activity (dpm 32P/micrograms phosphorus) of phosphatidylinositol 4-phosphate (PIP) and phosphatidylinositol 4,5-bisphosphate (PIP2) was not different between IDDM and control subjects. Under these conditions, basal 32Pi incorporation into PIP2 and PIP but not phosphatidylinositol (PI) or PA was significantly lower in IDDM subjects. There was significantly decreased [32P]PIP2 and [32P]PIP hydrolysis and decreased [32P]PA formation in IDDM after platelet stimulation with 4 U/ml human thrombin. There were no differences in [32P]PI hydrolysis between the two groups. The mass of PIP2 was reduced (P less than .005) in the platelets from IDDM (0.71 +/- 0.23 nmol/10(9) platelets) compared with control (1.65 +/- 0.53 nmol/10(9) platelets) subjects. Similarly, PIP was lower (P less than .001) in IDDM (0.66 +/- 0.09 nmol/10(9) platelets) than in control (2.92 +/- 0.43 nmol/10(9) platelets) subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

The inexhaustible beta cell.

Repeated intensive pancreatic beta-cell stimulation was carried out in 42 subjects, comprising 22 normal controls, 10 mild to "severe" maturity-onset diabetics, and 10 chronic pancreatitis patients. Each subject received 75 gm. oral glucose twice and 1 mg. glucagon plus 0.5 gm. tolbutamide intravenously three times at short intervals. Each of the three combined stimuli caused almost equivalent marked spikes of insulin release in all experimental groups. The total calculated output of insulin was equivalent to the total daily insulin output in normal subjects. Pancreatitics and those with severe diabetes (fasting blood sugar greater than 120 mg./100 ml.) had qualitatively similar but a quantitatively smaller response. Those with mild diabetes were similar to the normal subjects but had an exaggerated response to the second oral glucose dose, suggesting overactivity of the enteroinsular axis. Despite the inordinate insulin levels, hypoglycemia did not occur.

Immunoreactive glucagon responses to intravenous tolbutamide in chronic pancreatitis.

The effects of tolbutamide infusion (1 gm. over forty minutes) on plasma pancreatic glucagon-like immunoreactivity (PGLI), serum insulin, and blood glucose were studied in six patients with chronic pancreatitis and six matched controls.asal PGLI levels were significantly higher in the patients, despite higher fasting glucose concentrations. Tolbutamide infusion had no significant effect on mean PGLI levels in controls but was associated with significant elevation in pancreatitis patients, despite higher circulating glucose levels in the latter. The data suggest that chronic calcific pancreatitis patients hypersecrete immunoreactive glucagon, possibly from a nonpancreatic source and that this immunocreactive material may be stimulated by sulfonylureas.

Radionuclide assessment of left ventricular diastolic filling in diabetes mellitus with and without cardiac autonomic neuropathy.

Indexes of left ventricular diastolic filling were measured by radionuclide ventriculography in 28 patients with insulin-dependent diabetes mellitus without evidence of ischemic heart disease. Six patients (21%) had abnormal diastolic filling and differed from diabetic patients with normal filling in their greater severity of cardiac autonomic neuropathy, assessed by noninvasive means, and their lower plasma norepinephrine levels in the supine (131.1 +/- 24.7 versus 356.2 +/- 58.4 pg/ml, p less than 0.01) and upright (224.9 +/- 47.8 versus 673.3 +/- 122.3 pg/ml, p less than 0.005) positions. The diabetic patients determined as having cardiac autonomic neuropathy (n = 15) had depressed left ventricular diastolic filling compared with subjects free of autonomic neuropathy, whether measured as the time to peak filling rate (154.2 +/- 12.0 versus 119.1 +/- 10.6 ms, p less than 0.05) or the time to peak filling rate normalized to the cardiac cycle length (24.3 +/- 2.2 versus 16.2 +/- 1.5%, p less than 0.01). Of the various tests of autonomic nervous system function, the strongest correlate of impaired diastolic filling was orthostasis, measured as the decrease in systolic blood pressure with standing (r = 0.584, p less than 0.001). Thus, in patients with diabetes mellitus, alterations in sympathetic nervous system activity are associated with abnormalities of left ventricular diastolic filling.

Distinguishing features of idiopathic flushing and carcinoid syndrome.

We compared the clinical and biochemical profiles of 11 patients with idiopathic flushing (IF) with those of eight patients with carcinoid syndrome (CS). Patients with IF were more often women, had a longer duration of symptoms, and were younger. Palpitations, syncope, and hypotension occurred only in patients with IF, while wheezing and abdominal pain occurred only with CS; diarrhea occurred in both types of patients. Elevated blood serotonin levels were present primarily in CS. Increased levels of urine 5-hydroxyindoleacetic acid was specific for CS but unsufficiently sensitive to detect all cases. Abnormalities of gut and vasoactive peptides failed to distinguish the two conditions. Flushing in carcinoid patients responds uniformly to octreotide (Sandostatin), but only one third of the patients with IF are relieved of the symptom. Patients with IF have features that distinguish them from individuals with flushing from other causes, such as CS, postmenopausal state, chlorpropamide-alcohol flush, panic attacks, medullary thyroid carcinoma, and autonomic epilepsy. Familiarity with the clinical and biochemical features of IF should facilitate evaluation and identification of these patients.

Dietary fiber in management of diabetes.

Current evidence suggests that high-fiber diets, especially of the soluble variety, and soluble fiber supplements may offer some improvement in carbohydrate metabolism, lower total cholesterol and low-density lipoprotein (LDL) cholesterol, and have other beneficial effects in patients with non-insulin-dependent diabetes mellitus (NIDDM). Diets enriched with wheat bran and guar gum induce 10-20% reductions in serum cholesterol and LDL in both normo- and hypercholesterolemic subjects and have the ability to blunt the hypertriglyceridemic effects of diets high in carbohydrate and low in fiber. In insulin-dependent diabetes mellitus (IDDM) the situation is less clear, but a decrement of the circadian glucose profile has been shown. Americans, in general, consume too little fiber. With the need to restrict fat and reduce protein, an increase in carbohydrates is mandatory. A practical goal would be to establish the present level of fiber intake (15-30 g/day) and to gradually increase it. An intake of up to 40 g of fiber per day or 25 g/1000 kcal of food intake appears beneficial; in many individuals on weight-reducing diets higher levels may be unacceptable because of gastrointestinal side effects. The level of maximum benefit has not been determined. Fiber supplementation appears beneficial only if given with a diet comprising approximately half of the calories as carbohydrate. Foods should be selected with moderate to high amounts of dietary fiber from a wide variety of choices to include both soluble and insoluble types of fiber. Insufficient data are available on the long-term safety of high-fiber supplements. People at risk for deficiencies, such as postmenopausal women, the elderly, or growing children, may require supplements of calcium and trace minerals. People with upper gastrointestinal dysfunction are at risk of bezoar formation and cautioned against a diet high in fiber of the leafy vegetable type. Careful attention must be paid to insulin dose because hypoglycemia can result if there is a radical change in fiber intake and insulin dose is not reduced appropriately. Care must be exercised in the use of "novel" fibers, including the wood celluloses, because little is known of their safety and efficacy.

Effects of gemfibrozil on triglyceride levels in patients with NIDDM. Hyperlipidemia in Diabetes Investigators.

OBJECTIVE: Patients with NIDDM have a two- to fourfold increased risk of macrovascular disease. The constellation of elevated TGs and decreased HDL cholesterol are recognized as risk factors and constitute the major dyslipidemia in NIDDM. We therefore sought to determine if gemfibrozil (600 mg b.i.d.) was effective in correcting the dyslipidemia of NIDDM. RESEARCH DESIGN AND METHODS: After 8 wk of placebo stabilization, 442 patients from 46 study centers were randomized to double-blind treatment, in a designated 2:1 ratio, 295 received gemfibrozil and 147 received placebo for 20 wk. The primary end point was plasma TG; secondary end points were TC, LDL cholesterol, VLDL cholesterol, HDL cholesterol, and HbA1c. No baseline differences were noted between groups in sex, age, weight, type of diabetic therapy, fasting plasma levels of TGs, HbA1c, or C-peptide. About two-thirds received oral hypoglycemic drugs, one-third insulin. RESULTS: TG fell 26.4% in the gemfibrozil group and rose 7.4% in the placebo group (P < 0.023), by an intent-to-treat analysis. When patients who were noncompliant or with inadequate data were excluded, similar results were found--a 30.4% fall with gemfibrozil and a 4.8% increase with placebo (P < 0.0001). TG levels fell within 4 wk and remained low for 20 wk (P < 0.001). Mean HDL cholesterol rose by 4 wk and increased further at 12 wk (8-12%), P < 0.0001. TC fell. We observed a significant rise in LDL cholesterol in both gemfibrozil- and placebo-treated groups, with no significant differences between these groups. Changes in HbA1c were similar in gemfibrozil and placebo groups. No differences were observed in responses in groups treated with insulin and or oral hypoglycemic drugs. Overall AEs that were clinically important occurred in 6.1% in the gemfibrozil group vs. 2.0% in the placebo group (NS). CONCLUSIONS: We conclude that gemfibrozil is an effective and safe agent in combating the dyslipidemia of NIDDM, irrespective of type of diabetic therapy.

Cigarette smoking and neuropathy in diabetic patients.

We studied whether lifetime cigarette smoking is associated with the presence of diabetic neuropathy. The research design consisted of a case-control study conducted from a referral-based diabetes clinic at a major medical center. The patients were a 65% sample (163 insulin-dependent diabetes mellitus [IDDM] and 166 non-insulin-dependent diabetes mellitus [NIDDM] patients) of all patients admitted during a 26-mo period. Neuropathy was diagnosed on the basis of signs and symptoms. Smoking history was obtained by mailed questionnaire (66% response rate). Diabetes duration, HbA1, age, sex, peripheral vascular disease, hypertension history, and lifetime alcohol consumption were measured as covariates. The prevalence of neuropathy was 49 and 38% in IDDM (n = 113) and NIDDM (n = 104) patients, respectively. In IDDM, but not NIDDM, current or ex-smokers were significantly more likely to have neuropathy than individuals who had never smoked (odds ratio 2.46, P = 0.02), and the prevalence of neuropathy increased with increasing number of pack-years smoked (P less than 0.001). After adjustment for covariates, IDDM patients smoking greater than or equal to 30 pack-yr were 3.32 times more likely to have neuropathy than patients smoking less than this amount (95% confidence interval 1.15-9.58, P = 0.026). Cigarette smoking was associated with the presence of neuropathy in this clinic-based population of IDDM patients. The hypothesis that cigarette smoking is associated with diabetic neuropathy should be investigated further, both prospectively and in a more representative population.

Decreased exercise heart rate and blood pressure response in diabetic subjects with cardiac autonomic neuropathy.

Abnormal hemodynamic responses to exercise have been observed in diabetic subjects, but the pathogenesis and significance remain uncertain. We used maximal treadmill exercise to study 32 subjects with long-term insulin-dependent diabetes without clinical evidence of cardiac disease. Two of the 32 had occult ischemic heart disease revealed by stress electrocardiography and myocardial-perfusion scintigraphy and were excluded from subsequent analysis. In the remaining 30 subjects, we compared the responses to exercise of the 17 subjects with cardiac autonomic neuropathy diagnosed by noninvasive maneuvers (group 1) with the 13 without (group 2). At rest, the pressure-rate product (PRP) was higher in group 1 (114.0 +/- 5.7 vs. 95.9 +/- 5.3, P less than .05). With maximal exercise the increase in heart rate (44.6 +/- 4.8 vs. 79.0 +/- 5.4 beats/min, P less than .001), systolic blood pressure (36.8 +/- 5.9 vs. 55.0 +/- 5.8 mmHg, P = .02), and the PRP (102.0 +/- 7.3 vs. 182.0 +/- 8.2, P less than .001) were all lower in group 1 than in group 2, despite similar total treadmill times (631 +/- 47 vs. 587 +/- 40 s, P greater than .1). At each stage of exercise, the increase in heart rate and systolic blood pressure was lower in group 1 patients. The severity of cardiac autonomic neuropathy correlated inversely with the maximal increase in heart rate (r = -.68, P less than .001) and the PRP (r = -.58, P less than .005). Age, duration of diabetes, and the presence and severity of microvascular disease did not correlate with any of the hemodynamic parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

The natural progression of autonomic neuropathy and autonomic function tests in a cohort of people with IDDM.

OBJECTIVE: To test the natural progression of symptoms of autonomic neuropathy (AN) and function tests in subjects with IDDM. RESEARCH DESIGN AND METHODS: Seventy-six subjects with IDDM of < 10 years duration had cardiovascular autonomic reflex tests and were evaluated for signs and symptoms of AN. RESULTS: Fifty-seven subjects (66%) were available for restudy 9 years later (15 had died, 4 could not be located). Of the symptoms of AN, only gastroparesis increased in prevalence (P < 0.01). Of the five cardiovascular AN measures, only the R-R response to the Valsalva maneuver deteriorated (F[1,44] = 10.61, P < 0.01). CONCLUSIONS: The progression of AN in IDDM is monitored best longitudinally by the Valsalva maneuver because of the small variance ratio in repeated measures. Prevalence rates can be monitored by expiration-to-inspiration R-R or Valsalva ratios. Most clinical signs and symptoms of AN do not progress, underscoring the need for objective and quantitative autonomic function tests to identify people at risk for premature death.