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Biomedical subjects

A E Kitabchi

Publications and source records attributed to A E Kitabchi.

At least 19 recordsLinked to original sources

Hyperglycemic crises in urban blacks.

BACKGROUND: The hospital admission and mortality rates of patients with diabetic emergencies, such as diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar nonketotic syndrome (HHNS), are higher in black patients than in white patients with diabetes. However, there is limited data describing the precipitating events and response to treatment in black patients. Analysis of their clinical characteristics and response to medical therapy is needed to evaluate the impact of programs designed to reduce the development of these acute metabolic complications. METHODS: A prospective evaluation was conducted of 144 consecutive patients with DKA and 23 patients with HHNS admitted to a large inner-city hospital between July 1993 and October 1994. RESULTS: In patients previously diagnosed as having diabetes, poor compliance with insulin therapy was the major precipitating cause for DKA (49%) and HHNS (42%). Alcohol or cocaine abuse was a contributing factor for noncompliance and was present in 35% and 13% of patients with DKA and in 44% and 9% of patients with HHNS, respectively. Newly diagnosed diabetes accounted for 17% of patients with DKA and HHNS. Obesity (body mass index > 28 kg/m2 [the weight in kilograms divided by the square of the height in meters]) was present in 29% of patients with DKA and in 17% with HHNS and was most common in patients with DKA who were newly diagnosed as having diabetes (56%). Patients were treated by residents, who used a low-dose insulin protocol with an algorithm for insulin adjustment in 88 of 144 patients with DKA and 14 of 23 patients with HHNS. Although there was no difference in mortality rates or time needed to correct hyperglycemia or ketoacidosis, the use of the protocol significantly reduced the risk of hypoglycemia (5%) compared with patients treated without a protocol (23%) (P < .01). CONCLUSIONS: In urban black patients, poor compliance with insulin therapy was the main precipitating cause of acute metabolic decompensation, and substance abuse was a significant contributing factor for noncompliance. Obesity is common in black patients with DKA; it was present in more than half of those with newly diagnosed diabetes. Improved patient education and better access to medical care might reduce the development of these hyperglycemic emergencies.

Adult

NIDDM: new aspects of management.

Patients over age 40 should be made aware of the triad of risk factors for the disease and taught to recognize common signs and symptoms. Those with high-risk profiles should be tested regularly and counseled regarding preventive and therapeutic strategies. For obese patients whose weight cannot be brought under control with diet and exercise alone, a trial of anorectic agents should be considered.

Adult

Prevalence of undiagnosed non-insulin-dependent diabetes mellitus and impaired glucose tolerance in a cohort of older persons with hypertension.

OBJECTIVE: To determine the prevalence of undiagnosed non-insulin-dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT) in a cohort of older persons with hypertension. To examine the usefulness of screening for NIDDM in this study population. DESIGN: Cross-sectional study. SETTING: University of Tennessee, Memphis and the General Clinical Research Center (GCRC). PATIENTS: Ninety-five participants in the Trial of Nonpharmacologic Interventions in the Elderly (TONE) study who agreed to participate in an ancillary study. MEASUREMENTS: A standard oral glucose tolerance test (OGTT) with insulin and C-peptide levels was performed before the beginning of the TONE intervention. RESULTS: In this cohort, 43 participants (45.3%) had normal glucose tolerance (NGT), 41 (43.2%) had IGT, and 11 (11.6%) had undiagnosed NIDDM. The positive predictive value for NIDDM of a fasting glucose > or = 115 mg/dL in our participants was 57%. Hyperinsulinemia occurred in only one participant, a subject in the IGT group. CONCLUSIONS: Our data demonstrate that undiagnosed NIDDM is common in our cohort of older persons who are being treated for essential hypertension and that impaired glucose tolerance may be more common than in the general population of the same age. Further, our data show that the vast majority of this older, obese, hypertensive cohort did not have fasting hyperinsulinemia. We also infer that a fasting glucose alone has a low positive predictive value for screening of NIDDM in our older cohort. As the prevalence of NIDDM and impaired glucose tolerance in older hypertensive patients in the general population is unknown, we believe that further investigation is needed to characterize the relationship of hypertension, glycemic status, and hyperinsulinemia in the general population.

Aged

Differing effects of pancreas-kidney transplantation with systemic versus portal venous drainage on cholesteryl ester transfer in IDDM subjects.

OBJECTIVE: Cholesteryl ester transfer (CET) is accelerated in patients with IDDM treated with conventional (subcutaneous) insulin therapy (CIT) and a number of other disorders associated with premature cardiovascular disease. We have shown that in IDDM this disturbance is closely linked to iatrogenic hyperinsulinemia (HI), because it was reversed when insulin was administered by the intraportal (i.p.) route. In this study, we sought to determine whether HI after successful pancreas-kidney transplantation (PKT) has the same adverse effect on CET. RESEARCH DESIGN AND METHODS: CET was measured by both mass and isotopic assays and compared in two groups of euglycemic non-insulin-requiring IDDM PKT patients with either systemically draining allografts and persistent HI or grafts with portal vein anastomoses that were normoinsulinemic (PK-P). A third group of eight nondiabetic kidney transplant (KT) patients receiving the same immunosuppressive drugs served as control subjects. RESULTS: CET in pancreas-kidney transplantation subjects with systemic venous drainage (PK-S) was increased (P < 0.001) to the same level we have reported previously in IDDM patients receiving CIT and was significantly higher (P < 0.001) than in those subjects with PK-P. CET in the PK-P group did not differ from that of the KT control patients. CONCLUSIONS: CET is affected by variations in systemic insulin levels in pancreas transplant patients with allografts that have differing venous drainage. Because high systemic insulin levels are linked to the activation of (ET, euglycemic HI IDDM pancreas allograft recipients may continue to be at high risk for macrovascular complications.

Adult

Diabetic ketoacidosis.

This article reviews the pathogenesis of diabetic ketoacidosis (DKA) and provides a rational approach to the management of patients with DKA. The therapeutic discussion includes the use of low-dose insulin, no bicarbonate, or phosphate therapy on the majority of DKA patients, based on numerous prospective randomized studies. The article also discusses controversial subjects such as the use of hypotonic versus isotonic saline with and without colloids, hydration of subjects before insulin therapy, and admission of DKA patients to the general ward versus emergency ward versus intensive care unit. A concise, simple protocol is also presented as a suitable reference for management of patients with DKA.

Acidosis

Results of pancreas transplantation with portal venous and enteric drainage.

PURPOSE: The standard method for pancreatic transplantation involves drainage of exocrine secretions into the urinary bladder with venous outflow into the systemic circulation. Despite the high success rate associated with this approach, it often leads to complications, including chemical cystitis, reflux pancreatitis, metabolic acidosis, and hyperinsulinemia. The authors developed a new technique of pancreatic transplantation with portal drainage of endocrine secretions and enteric drainage of exocrine secretions (PE), which theoretically should be more physiologic. PROCEDURES: All patients were insulin-dependent diabetics with end-stage renal disease who underwent combined kidney-pancreas transplantation. Between 1990 and 1994, 19 patients have been transplanted using intraperitoneal placement of the pancreas allograft with exocrine drainage into a Roux-en Y loop and venous drainage into the portal circulations (PE). A comparison group of all patients undergoing standard systemic-bladder (SB) transplantation between April 1989 and March 1993 (n = 28) also was studied. Patient follow-up ranges from 6 months to 5 years for the SB patients (mean = 2.5 years) and 6 months to 4 years for the PE patients (mean = 1.6 years). Routine follow-up includes documentation of the clinical course and detailed endocrine studies. FINDINGS: Patient and graft actuarial survival at 1 and 3 years is no different for SB and PE patients. Urinary tract infections occurred in 89.3% of the SB patients (2.8/patient) versus 26.3% of the PE patients (0.25/patient, p < or = 0.0001). None of the PE patients experienced hematuria compared with 53.6% of the SB patients (p < or = 0.0001); however, two PE patients had melanotic episodes. The incidence of urinary retention and reflux pancreatitis was 32.1% versus 5.3% (p < or = 0.028) for SB and PE groups, respectively. Patients in the SB group required sodium bicarbonate therapy (mean = 55 mEq/day) although no PE patient required routine therapy; despite this, SB patients experienced more episodes of acidosis (44 vs. 5). Endocrine studies indicate no difference in glycosylated hemoglobin or fasting and stimulated glucose values throughout the follow-up period. In contrast, hyperinsulinemia was evident in both fasting and stimulated tests for the SB patients, with values consistently two- to fivefold higher than those of the PE group. CONCLUSIONS: These results indicate that PE and SB pancreas transplantation are equivalent in terms of patient and graft survival and suggest that the PE approach is associated with a decreased incidence of metabolic and bladder-related complications. In addition, the PE approach eliminates the state of peripheral hyperinsulinemia that characterizes the SB procedure. Continued follow-up will be necessary to determine if long-term outcomes will differ for patients with PE and SB grafts.

Actuarial Analysis

Genetic and immunological markers of insulin dependent diabetes in Black Americans.

ICA and GAD65 autoantibody profiles and HLA-DR and DQ analysis were performed on 43 Black juvenile onset IDDM patients and 34 unrelated Black controls from Tennessee, USA. 75% of patients were positive for GAD65 autoantibodies but only 53% had ICA; 39% both ICA and GAD65 antibodies. The strongest HLA association was with the DR3 haplotype DRB1*03 DQA1*0501 DQB1*0201 (63% of patients v 12% of controls RR = 13.0, p < 0.00002). DRB1*04 DQA1*0301 DQB1*0302, associated with IDDM in Caucasians but rare in Negroids, occurred in 27% of patients and 6% of controls (RR = 5.9, p < 0.04). All patients carried DQB1*0302 or DQB1*0201. DQB1*0602 was significantly reduced in patients (2.4% v 41%, RR = 0.036, p < 0.008) and DRB1*1501 was absent in patients (0% v 35%). The frequency of GAD65 autoantibodies in Black American IDDM patients is comparable to that in Caucasians; however ICA positivity is reduced. GAD65 antibodies may therefore be a more sensitive serological test to identify individuals in the Black American general population for markers associated with increased risk of developing IDDM. Current screening methods for predicting preclinical IDDM in Caucasians relies on a combination of immune and HLA markers of IDDM; studies of these markers in the Black Americans will make it possible to extend these options to additional genetically diverse populations.

Adolescent

Evidence for a defect in insulin metabolism in hyperandrogenic women with polycystic ovarian syndrome.

It has been well established that the hypertestosteronemia of patients with polycystic ovarian syndrome (PCO) is associated with hyperinsulinemia and insulin resistance. We have recently noted a disparity between serum levels of insulin and C-peptide in certain hypertestosteronemic women with PCO and hypothesized a possible association between testosterone and insulin metabolism. Therefore, we have studied insulin clearance (baseline steady-state ratios of C-peptide to insulin) in 15 obese PCO women, 12 weight-matched controls (OC), and nine lean controls (LC), and examined the interactions of testosterone and insulin metabolism by examining the correlations between testosterone and insulin clearance and by studying the direct in vitro actions of testosterone on T-lymphocyte insulin binding and degradation. We found that the C-peptide to insulin ratio at baseline and T-lymphocyte insulin degradation of the PCO group were twofold below the LC and OC values. Basal C-peptide to insulin ratios and insulin-degradative activities were significantly and negatively interrelated (r = .56, P < .01), and both of these parameters were highly correlated (P < .01) with basal testosterone levels (r = .49 for basal C-peptide to insulin and r = -.61 for insulin degradation). In experiments where testosterone was added to cell cultures, insulin degradation was impaired in a biphasic fashion. We conclude that (1) elevated testosterone levels may contribute to impairments in insulin metabolism, and (2) the hyperinsulinemia of hyperandrogenic women may occur in part from defects in insulin clearance and peripheral tissue insulin degradation.

Adult

Enhanced adrenocortical activity as a contributing factor to diabetes in hyperandrogenic women.

The high incidence of non-insulin-dependent diabetes mellitus (NIDDM) in women with polycystic ovarian syndrome (PCO) is believed to occur secondary to the insulin resistance associated with their androgenicity. In the present study, we have examined the interrelationships between glucose tolerance, androgenicity, and various in vivo and in vitro parameters of insulin sensitivity in 11 obese PCO patients with NIDDM, 14 PCO patients without diabetes, and 14 weight-matched controls. Both groups of PCO patients were hypertestosteronemic, hyperinsulinemic, and insulin-resistant when compared with a group of weight-matched controls. However, PCO patients with NIDDM differed from those without diabetes in that they had elevated basal and corticotropin-stimulated adrenal steroids (cortisol, dehydroepiandrosterone [DHEA], dehydroepiandrosterone sulfate [DHEAS]). The hyperglycemia of our diabetic patients was not related to their elevated testosterone levels or to their degree of insulin resistance, but was significantly and positively correlated with adrenal hypersecretion, which in turn was associated with postreceptor defects in insulin action. These findings would suggest that enhanced adrenocortical activity may be an important factor underlying the development of NIDDM in women with PCO.

Adrenal Cortex

Case report: amelioration of insulin resistance in diabetes with dehydroepiandrosterone.

In hyperandrogenic females, the ratio of dehydroepiandrosterone (DHEA) to testosterone may be an important determinant of insulin sensitivity. This study involved changes in insulin sensitivity and glucose metabolism with therapeutic manipulation of DHEA (S)/testosterone in a female patient with non-insulin-dependent diabetes and hyperandrogenism. Therapeutic intervention included 1-month treatment with 0.25 mg dexamethasone at bedtime and 1-month dexamethasone + DHEA. Insulin sensitivity and glucose tolerance were assessed before and after each treatment regimen by examining: 1) fasting and oral glucose tolerance test glucose and insulin levels, 2) hypoglycemic response to intravenous insulin, and 3) erythrocyte insulin receptor binding. With dexamethasone alone, DHEAS, testosterone, and their ratio were reduced with a concomitant increase (30%) in oral glucose tolerance test insulin levels and a decrease (33%) in erythrocyte insulin binding. With DHEA + dexamethasone, the ratio of DHEAS/testosterone increased 16-fold along with a marked improvement in insulin sensitivity, as determined by a more than 30% reduction in fasting and oral glucose tolerance test insulin levels, a threefold stimulation of the rate of glucose disappearance with intravenous insulin, and a 30% increase in insulin binding. DHEA improved insulin sensitivity and reduced fasting and oral glucose tolerance test glucose levels and ameliorated the diabetic state. The ratio of DHEAS/testosterone is an important regulator of insulin sensitivity and glucose tolerance and that DHEA therapy may be beneficial in the treatment of certain forms of insulin resistance.

Adolescent

Role of adrenal and gonadal androgens in insulin action and metabolism.

In a previous report we found extreme hyperinsulinemia associated with high testosterone levels in patients with polycystic ovarian syndrome (PCO) and normal insulin levels in a small group of patients with elevated dehydroepiandrosterone (DHEA). From these observations, we hypothesized that DHEA and testosterone may have opposing actions on insulin sensitivity. To test this hypothesis, we studied insulin sensitivity in vivo and in vitro in a) obese PCO women with elevated testosterone, b) obese patients with adult-onset adrenal hyperplasia (AH) and high levels of DHEA, c) weight-matched obese controls, and d) lean controls. Insulin sensitivity was determined by insulin responses to a standard OGTT, hypoglycemic responses to an IV insulin tolerance test (ITT), red blood cell (RBC) insulin binding and receptor kinase activity, and phytohemagglutinin (PHA)-activated T-lymphocyte (T-cell) insulin binding and PDH insulin sensitivity. In PCO patients, we found that basal and glucose-challenged insulin levels were significantly greater than, and hypoglycemic responses to IV insulin, significantly lower than, weight-matched control values. However, AH patients had insulin values significantly below, and hypoglycemic responses significantly above, those of the weight-matched controls. Their values were, in fact, comparable to those observed for the lean control subjects. Similar findings were observed with insulin binding and PDH insulin sensitivity. Insulin sensitivity in all study subjects was found to be negatively correlated to testosterone and positively correlated to DHEA and, more significantly, to the ratio of DHEA/testosterone. These data would suggest that, in females, DHEA and T may have opposing actions on insulin sensitivity. We conclude that in females insulin sensitivity in vivo and in vitro is modulated, at least in part, by the ratios of DHEA to testosterone.

Adrenal Glands

Pseudonormoglycemia in diabetic ketoacidosis with elevated triglycerides.

A 24-year-old newly diagnosed male patient with diabetes presented with diabetic ketoacidosis (DKA) (pH 7.16, HCO3 6.0) and extreme hypertriglyceridemia (239.35 mmol/L). The diagnosis of DKA was delayed because of the apparent depression of the true serum glucose (to 11 mmol/L). He was treated with intravenous (IV) insulin and rehydration, which normalized his pH, HCO3, and triglyceride levels. To the authors' knowledge, this is both the highest triglyceride level recorded and the first report of a high triglyceride level as the apparent cause of a factitiously low glucose level.

Adult

Opposing actions of dehydroepiandrosterone and testosterone on insulin sensitivity. In vivo and in vitro studies of hyperandrogenic females.

It has been hypothesized that the androgens testosterone and dehydroepiandrosterone (DHEA) may have opposing actions on insulin sensitivity. To test this hypothesis, we selected patients with polycystic ovary syndrome (PCO) and hypertestosteronemia and a group of individuals with adrenal hyperplasia (AH) and elevated DHEA and studied their 1) insulin and glucose responses to a 75-g oral glucose tolerance test, 2) insulin resistance by hypoglycemic responses to a standard dose of intravenous (IV) insulin, and 3) insulin binding and pyruvate dehydrogenase (PDH) responsiveness to insulin in phytohemagglutinin (PHA)-activated T lymphocytes. PCO patients exhibited elevated basal and glucose-challenged insulin levels and had blunted hypoglycemic responses to IV insulin. Conversely, AH patients had hypoglycemic responses to IV insulin significantly greater than and basal and glucose-challenged insulin levels lower than the PCO patients and weight-matched control subjects. In vitro, T-lymphocyte insulin binding of the PCO patients was 40-60% below control values; in AH patients, insulin binding and PDH insulin sensitivity were above those of the control subjects. Testosterone levels in all study subjects were negatively correlated to T-lymphocyte insulin binding and positively correlated to basal insulin, insulin area under the curve (AUC), and insulin-glucose indices. DHEA levels were positively correlated to insulin binding and inversely related to basal insulin, insulin AUC, and insulin-glucose indices. In all instances, the parameters of insulin sensitivity were more strongly correlated to individuals' ratios of DHEA to testosterone than to either of these androgens alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenocortical Hyperfunction

Bimodal correlation between the circulating insulin level and the production rate of dehydroepiandrosterone: positive correlation in controls and negative correlation in the polycystic ovary syndrome with acanthosis nigricans.

The objective of this study was to define the relationship among the circulating insulin level (IRI), the MCR of dehydroepiandrosterone (MCR-D), and the production rate of DHEA (PR-D) in 10 women with the polycystic ovary syndrome and acanthosis nigricans (PCOS-AN). Seven normal weight and 10 obese women served as controls. Measurement of the MCR-D and PR-D was accomplished by iv saline infusion (0.9% NaCl solution) on day 1 as a control and a 4-h iv dehydroepiandrosterone (unlabeled) infusion (1 mg/h) was performed on day 2. Mean MCR-D was more than 2-fold higher in the obese controls compared to the normal weight controls. However, the plasma concentration of DHEA(PC-D) was not significantly different in the normal and obese control women, since the PR-D was increased proportionately to the MCR-D. The MCR-D and the PR-D were coupled through insulin in the control women, and their correlation coefficients with IRI were positive and identical (0.77 and 0.73, respectively). In contrast, IRI was negatively correlated with PR-D in the PCOS-AN women. Also, unlike the control women, there was minimal or no change in the MCR-D across a broad range of IRI in the PCOS-AN women. Thus, the MCR-D and PR-D were not coupled in these women.

Acanthosis Nigricans

Sensitivity of pyruvate dehydrogenase to insulin in activated T lymphocytes. Lack of responsiveness to insulin in patients with polycystic ovarian disease and diabetes.

Using phytohemagglutinin-activated T lymphocytes, we studied possible mechanisms responsible for insulin resistance in patients with polycystic ovarian disease (PCO) and acanthosis nigricans (AN) by examining insulin binding to erythrocytes and activated T lymphocytes and T-lymphocyte pyruvate dehydrogenase (PDH) responsiveness to insulin in three groups. These groups of subjects consisted of six PCO-AN patients with normal glucose tolerance, six PCO-AN patients with mild non-insulin-dependent diabetes mellitus (NIDDM), and six weight-matched control subjects. We found that insulin binding to both erythrocytes and activated T lymphocytes was significantly lower in PCO and PCO-NIDDM patients than control subjects but did not differ between the PCO groups. Insulin binding to erythrocytes and T lymphocytes varied inversely with basal insulin. In activated T lymphocytes of PCO-NIDDM patients, PDH responsiveness to both submaximal and maximal insulin concentrations was impaired, the extent of which varied in proportion to their degree of carbohydrate intolerance. In contrast, PDH responsiveness to maximal amounts of insulin in T lymphocytes of PCO patients without NIDDM was similar to the weight-matched control subjects. These data may suggest that lesions at the level of the receptor are primarily responsible for insulin resistance in patients with PCO but that both receptor and postreceptor defects (i.e., PDH responsiveness to insulin) contribute to the insulin-resistant state of PCO patients with NIDDM.

Adolescent

Identification of insulin intermediates and sites of cleavage of native insulin by insulin protease from human fibroblasts.

We have studied the time sequence degradation of native insulin by insulin protease from human fibroblast using multiple steps involving purification of the products by high performance liquid chromatography, determination of peak composition by amino acid sequence analysis, and confirmation of structure by mass spectrometry and thus elucidated the sites of cleavage of insulin by human insulin protease. We observed that as early as 0.5 min of incubation, three major new peptide peaks, intact insulin, and four smaller peptide peaks can be detected. The major peptides are portions of the insulin molecule, with the amino ends of the A and B chains or the carboxyl ends of the A and B chains still connected by disulfide bonds. Peptide peak I is A1-13-B1-9. Peptide peak II is A1-14-B1-9. Peptide peak III is A14-21-B14-30. The smaller peptide peaks are A14-21-B17-30, A15-21-B14-30, A15-21-B10-30, and A14-21-B10-30. The major peptide bond cleavage sites therefore consist of A13-14, A14-15, B9-10, B13-14, and B10-17. With longer incubation times, peptide peak II appears to lose the A14 tyrosine to form peptide peak I. This peptide I, which is the amino end of the A and B chains, is not further degraded even after 1.5 h of incubation. With longer incubation times, the peptides containing the carboxyl ends of the A and B chains are further degraded to form products from cleavage at the A18-19, B14-15, B25-26, and a small amount of A19-20, B10-11, and B24-25 cleavage and the emergence of 2-5-amino acid peptide chains, tyrosine, alanine, histidine, and leucine-tyrosine. We conclude, based on the three-dimensional structure of insulin, that human insulin protease recognizes the alpha-helical regions around leucine-tyrosine bonds and that final degradation steps to small peptides do not require lysosomal involvement.

Amino Acid Sequence