Diabetes mellitus and arsenic exposure: a second look at case-control data from a Swedish copper smelter

OBJECTIVES

To find out whether a newly found association between diabetes mellitus and arsenic in drinking water in Taiwan could be reproduced in copper smelters with arsenic exposure.

METHODS

Extended analysis of a previous case-control study from 1978 was based on death records and objective exposure information from the company. The final analysis included only those employed at the smelter. Cases were 12 people with diabetes mellitus on the death certificate and those for whom there was clinical information on this disease. Controls were 31 people without cancer, cardiovascular and cerebrovascular disease as these disease categories had been associated with arsenic exposure in the original study and elsewhere.

RESULTS

The odds ratios found for diabetes mellitus with increasing arsenic exposure categories were (reference level = 1), 2.0, 4.2, and 7.0, but the 95% confidence intervals included unity. Unstratified test for trend was weakly significant, P = 0.03.

CONCLUSIONS

Although based on small numbers, the findings provide some support for the suggestion that arsenic exposure could sometimes play a part in the development of diabetes mellitus.

Diabetes mellitus associated with pentamidine isethionate in diffuse cutaneous leishmaniasis

The authors report a case of a male patient from Bacabal, MA with diffuse cutaneous leishmaniasis (DCL), for at least nine years, with 168 lesions on his body. These were tumour-like nodules with some ulceration. He used pentavalent antimonial (glucantime) and an association of gamma interferon plus glucantime with improvement of the lesions but relapsed later. Recently, pentamidine isethionate (pentacarinat) was given a dosage of 4mg/kg/weight/day on alternate days for 20 applications. After 3 months a similar course of 10 application was given 2 times. Later he developed diabetic signs with weight loss of 10kg, polydypsia, polyuria and xerostomia. The lower limbs lesions showed signs of activity. Blood glucose levels normalised and remain like this at moment. Attention is drawn to the fact that pentamidine isethionate should be used as a therapy option with care, obeying rigorous laboratory controls including a glucose tolerance test.

Complications of growth hormone therapy in children

The introduction of human growth hormone (GH) prepared by recombinant DNA technology has resulted in increased numbers of children and adults receiving treatment. This trend has led to questions concerning the safety of GH, particularly when used for indications other than GH deficiency. This review discusses the effects of GH on fluid, lipid, and carbohydrate metabolism; the risk of intracranial hypertension or pseudotumor cerebri; the effects on the skeletal system; the risk of malignancy; and the effects on the immune system. At present, GH treatment appears to be safe, although long-term follow-up of GH-treated patients is necessary.

Cycad toxin-induced damage of rodent and human pancreatic beta-cells

Environmental toxins may be risk factors for some forms of diabetes mellitus and neurodegenerative diseases. The medicinal and food use of seed from the cycad plant (Cycas spp.), which contains the genotoxin cycasin, is a proposed etiological factor for amyotrophic lateral sclerosis/Parkinsonism-dementia complex (ALS/PDC), a prototypical neurodegenerative disease found in the western Pacific. Patients with ALS/PDC have a very high prevalence of glucose intolerance and diabetes mellitus (in the range of 50-80%). We investigated whether the cycad plant toxin cycasin (methylazoxymethanol (MAM) beta-D-glucoside) or the aglycone MAM are toxic in vitro to mouse or human pancreatic islets of Langerhans. Mouse pancreatic islets treated for 6 days with cycasin impaired the beta-cell insulin response to glucose, but this effect was reversible after a further 4 days in culture without the toxin. When mouse islets were exposed for 24 hr to MAM/MAM acetate (MAMOAc; 0.1-1.0 mM), there was a dose-dependent impairment in insulin release and glucose metabolism, and a significant decrease in islet insulin and DNA content. At higher MAM/MAMOAc concentrations (1.0 mM), widespread islet cell destruction was observed. Glucose-induced insulin release remained impaired even after removal of MAM and a further culturing for 4 days without the toxin. MAM damages islets by two possible mechanisms: (a) nitric oxide generation, as judged by increased medium nitrite accumulation; and (b) DNA alkylation, as judged by increased levels of O6-methyldeoxyguanosine in cellular DNA. Incubation of mouse islets with hemin (10 or 100 microM), a nitric oxide scavenger, or nicotinamide (5-20 mM) protected beta-cells from a decrease in glucose oxidation by MAM. In separate studies, a 24 hr treatment of human beta-islet cells with MAMOAc (1.0 mM) produced a significant decrease in both insulin content and release in response to glucose. In conclusion, the present data indicate that cycasin and its aglycone MAM impair both rodent and human beta-cell function which may lead to the death of pancreatic islet cells. These data suggest that a "slow toxin" may be a common aetiological factor for both diabetes mellitus and neurodegenerative disease.

[A case of tacrolimus-induced glucose intolerance following renal allografting]

Living renal transplantation (Tx) was carried out on a 41-year-old male undergoing hemodialysis for a six-month period because of end-stage renal failure due to chronic glomerulonephritis. Tacrolimus (FK 506) was used as one of immunosuppressants. The graft worked immediately after Tx. However, his blood sugar level rose extremely high and use of insulin (IS) was required. At the second postoperative day, 0.3 mg/kg/day of FK506 was administered and the trough level (TL) was as high as 65 ng/ml. The serum IS level decreased from the pre-Tx value of 22 microU/ml to 12 microU/ml. With decrease in the dose of FK506, the TL was normalized, and the dose of IS could be decreased. FK506 has been reported to inhibit IS secretion. Therefore, we must be careful to evaluate the blood glucose level in the use of FK506 for patients with poor glucose tolerance.

Carbohydrate tolerance in patients with tropical ataxic neuropathy--A human model of chronic cyanide intoxication

Patients with tropical ataxic neuropathy (TAN) have been shown to have chronic cyanide intoxication. Glucose tolerance test data in a group of 88 patients with TAN and 88 matched controls who were studied several years ago were analysed. A standard glucose tolerance test (SGTT) with 50 gm dextrose preceded by 50 mgs cortisone acetate orally 8 1/2 and 2 hours before the tests were performed. The SGTT was considered abnormal if the capillary blood glucose at 0.60 and 120 were greater than 120, 200 and 140 mg/100 ml (6.6, 11.1, 7.8 mmol/l) respectively. Capillary blood glucose considered abnormal for CGTT were 205 and 155 mg/100 ml at 60 and 120 (113 and 8.6 mmol/I) respectively. The SGTT was abnormal in 1 of the TAN patients and 2 controls while CGTT was abnormal in 9 TAN patients and 7 controls. However, all controls with abnormal CGTT were older than 50 years while only 1 TAN patient was older than 50 and 6 were 30 years or younger (p = 0.0105), Fischer's probability test. The results suggest a greater statistical risk for subjects with TAN 30 years or younger to have an abnormal CGTT. While this does not predict the future development of diabetes, our observation indicates the need for better designed prospective studies among such patients in developing countries.

Recombinant human insulin-like growth factor-I enhances whole body protein anabolism and significantly diminishes the protein catabolic effects of prednisone in humans without a diabetogenic effect

To investigate whether recombinant human insulin-like growth factor-I (rhIGF-I) could serve as a protein-sparing nondiabetogenic agent, 21 healthy volunteers (mean age, 25 +/- 1 yr) were studied in 3 similar clinical models: rhIGF-I alone, rhIGF-I and prednisone, and prednisone alone. In study A, 6 subjects received infusions of [14C]leucine and [2H2]glucose before and after 5-7 days of rhIGF-I (100 micrograms/kg, sc, twice daily, followed by 16 h of a 10 micrograms/kg.h continuous sc infusion). The rate of appearance (Ra) of leucine, an estimate of whole body proteolysis, did not change significantly, whereas leucine oxidation decreased (-31 +/- 4%; P = 0.001), hence the nonoxidative leucine disposal (NOLD) increased significantly (P = 0.04). These effects are similar to those reported with high dose hGH. Plasma glucose concentrations did not change despite a significant reduction in circulating insulin concentrations (-58 +/- 11%; P = 0.01) and an increase in the glucose Ra (+12 +/- 5%; P = 0.04). After rhIGF-I treatment, plasma IGF-I, IGF-binding protein-1 (IGFBP-1), and IGFBP-2 all increased significantly, whereas IGFBP-3 did not change. In study B, seven subjects received rhIGF-I combined with oral prednisone (0.8 mg/kg.day) for 5 days. Group C (n = 8) received only prednisone. In group B, both the leucine Ra and oxidation increased (Ra, +7 +/- 3%; oxidation, +45 +/- 13%), but this increase was significantly less than that seen in group C (Ra, +25 +/- 5%; oxidation, 117 +/- 17%; P < 0.005 vs. group B). Group B showed no significant changes in postabsorptive glucose concentrations despite marked reductions in circulating insulin levels, in contrast to the increase in insulin and glucose concentrations observed in group C. In conclusion, 100 micrograms/g rhIGF-I, given twice daily, 1) has GH-like effects on whole body protein metabolism, 2) markedly diminishes the protein catabolic effect of glucocorticosteroids, and 3) is nondiabetogenic in prednisone-treated humans. This agent offers promise in the treatment of protein catabolic states.

Do immunosuppressants cause posttransplant diabetes mellitus?

BACKGROUND

Posttransplant diabetes mellitus (PTDM) was originally described by Starzl in 1964. The incidence is around 3-46%, according to several reports. Etiologies and risk factors of PTDM have been discussed after it was described and recognized as a complication of renal transplantation.

METHODS

Twenty-five consecutive renal transplants in 24 recipients were reviewed, and 3 cases of posttransplant diabetes mellitus were found. Cyclosporine A (CsA), Azathioprine (Aza) dose and maintenance dose of Prednisolone (Pred.), rejection episodes, total dosage of steroid used at the time of acute rejection were carefully recorded and analyzed.

RESULTS

The mean age of 3 living-related and 22 cadaveric transplant recipients was 32.7 +/- 7.5 and 33.5 +/- 6.8 years in PTDM and non-PTDM patients, and the onset of PTDM was, on the average, 11.3 +/- 10.6 months. Comparative studies between non-PTDM and PTDM groups showed that age, rejection episodes, total dose of methylprednisolone used in acute rejection, CsA level, and dosage of CsA, Aza and prednisolone at 1,6,12 and 24 months were not significantly different from one another.

CONCLUSIONS

No significant risk factors or definitive mechanism involved in the development of PTDM were identified in this study. It is suggested that immunosuppressants are involved in the occurrence of PTDM, and probably neither a single factor is responsible nor is dose dependency involved.

Pentamidine-induced derangements of glucose homeostasis. Determinant roles of renal failure and drug accumulation. A study of 128 patients

OBJECTIVE

To assess the prevalence, presentation, and risk factors of pentamidine-induced dysglycemia.

RESEARCH DESIGN AND METHODS

Blood glucose values were screened in 244 consecutive immunocompromised patients with Pneumocystis carinii pneumonia: 116 being treated with cotrimoxazole and 128 others with pentamidine.

RESULTS

Two cotrimoxazole patients developed diabetes as a result of necrotizing pancreatitis (1.7%); the others remained euglycemic. Forty-eight pentamidine-treated patients (38.5%) developed severe glucose homeostasis disorders: hypoglycemia in 7, hypoglycemia and then diabetes in 18, and diabetes alone in 23 (P < 0.001 vs. the cotrimoxazole group). Hypoglycemia was early, sudden, often recurrent, and life-threatening, associated with inappropriately high insulin levels in plasma; the B-cell response to stimuli was poor. Of the 41 diabetic patients, 26 required insulin therapy; their plasma C-peptide levels were lower than normal, and the B-cell secretory responses to stimuli were poor. Islet cell antibodies, insulin antibodies, and insulitis were not detected. The pentamidine-treated dysglycemic patients differed from their euglycemic counterparts by higher pentamidine doses (P < 0.001), higher plasma creatinine levels (P < 0.001), and more severe anoxia (P < 0.05) and shock (P < 0.001). Most of them had received pentamidine mesylate parenterally (n = 36; 75%); six others received the isethionate salt and six exclusively pentamidine aerosols.

CONCLUSIONS

Pentamidine-induced dysglycemic accidents are primarily due to inappropriate insulin release and toxicity to the islet B-cells. Drug accumulation due to excessive doses, iterative courses, and/or renal impairment is the determining risk factor.

Effect of octreotide on glucose tolerance in acromegaly

To determine the effect of the somatostatin analog octreotide on glucose tolerance in acromegaly, we examined glucose profiles, oral glucose tolerance and the insulinogenic index in patients treated with this analog. Ninety patients participated in a long-term, prospective, open-label study. There was no significant change between mean daily blood glucose profiles at baseline or during octreotide treatment. Using glucose tolerance test criteria, 61% of 90 patients had normal baseline glucose tolerance. While on octreotide, 20% and 29% of these patients, respectively, developed impaired glucose tolerance or became frankly diabetic. Conversely, three of the patients who were diabetic at baseline (N = 11) became normal (18%) or developed impaired glucose tolerance (9%) during octreotide therapy. There was no relationship between the dose of octreotide and change in glycemic state. The insulinogenic index (insulin/glucose) response to a glucose challenge decreased uniformly in octreotide-treated patients. Female patients and those with elevated baseline insulin levels were more likely to develop diabetes mellitus during octreotide therapy. In conclusion, octreotide significantly alters glucose tolerance in patients with acromegaly, mandating glucose monitoring during this form of therapy.

Steroid-related complications in the cyclosporine era

Steroid withdrawal has potential risks (rejection) and benefits (fewer complications). Most data on steroid-related complications predates cyclosporine (CsA). We tabulated the incidence of posttransplant complications considered to be steroid-related in 748 adult kidney transplant recipients (with at least 1 year of follow-up) on CsA and prednisone. Using logistic regression analysis, we considered the effects of pre- and postoperative variables for these complications: cataracts; new-onset post-transplant diabetes; bone/joint complications; avascular necrosis; and posttransplant hypertension. Variables included pretransplant steroid therapy; initial steroid dose; prednisone dose at 1 month and 1 year; steroid-treated rejection episodes; cumulative time on steroids; sex; age; race; pretransplant hypertension; pretransplant diabetes; donor source; nonsteroid treated rejection episodes; other immunosuppressive therapy; cumulative time on dialysis; and previous renal or extrarenal transplants. Cataracts occurred in 21.1%, new-onset posttransplant diabetes in 7.6%, bone/joint complications in 49.9%, avascular necrosis in 5.5%, and post-transplant hypertension in 74.9% of recipients. Significant variables for cataract development were prednisone dose at 1 year (odds ratio [OR] = 1.32; p < 0.05), cumulative time on steroids (OR = 1.65; p < 0.001), age > 50 years (OR = 1.85; p < 0.0001), and pretransplant diabetes (OR = 1.63; p < 0.0001). For new-onset posttransplant diabetes, age > 50 years (OR = 1.63; p < 0.05) and nonwhite race (OR = 2.12; p < 0.001) were significant. For bone/joint complications, cumulative time on steroids was significant (OR = 1.45; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Ingested inorganic arsenic and prevalence of diabetes mellitus

To examine the association between ingested inorganic arsenic and prevalence of diabetes mellitus, in 1988, the authors studied 891 adults residing in villages in southern Taiwan where arseniasis is hyperendemic. The status of diabetes mellitus was determined by an oral glucose tolerance test and a history of diabetes regularly treated with sulfonylurea or insulin. The cumulative arsenic exposure in parts per million-years was calculated from the detailed history of residential addresses and duration of drinking artesian well water obtained through standardized interviews based on a structured questionnaire and the arsenic concentration in well water. The body mass index was derived from body height and weight measured according to a standard protocol, while the physical activity at work was also obtained by questionnaire interviews. Residents in villages where the chronic arseniasis was hyperendemic had a twofold increase in age- and sex-adjusted prevalence of diabetes mellitus compared with residents in Taipei City and the Taiwan area. There was a dose-response relation between cumulative arsenic exposure and prevalence of diabetes mellitus. The relation remained significant after adjustment for age, sex, body mass index, and activity level at work by a multiple logistic regression analysis giving a multivariate-adjusted odds ratio of 6.61 and 10.05, respectively, for those who had a cumulative arsenic exposure of 0.1-15.0 and greater than 15.0 ppm-year compared with those who were unexposed. These results suggest the chronic arsenic exposure may induce diabetes mellitus in humans.

Surgical aspects of live donor kidney transplants in Kenya

Review of twenty cases of live-donor kidney transplants in Kenya for a period of 5 years (1985-1989) and the follow up study results revealed that there were both high graft losses, high morbidity and mortality due to various complications pertaining to surgery and immunosuppression. The most serious complications were intercurrent infections, acute or chronic rejection, pulmonary embolism, steroid induced diabetes, pneumonia, and myocardial infarction. At the end of the first year follow up, there were only twelve graft patients alive. Magnetic Resonance Imaging (MRI) was not available for assessing the anatomical and functional behaviour of the transplanted kidneys. This would have assisted in early diagnosis of the degree and onset of rejection for appropriate treatment before the death of the allografts. It would also assist in differentiating perfusional problems from rejection.

Insulin requirements after liver transplantation and FK-506 immunosuppression

Hyperglycemia and new-onset diabetes mellitus is a well-recognized complication of solid organ transplantation. With the advent of FK-506 as a new immunosuppressive drug used in orthotopic liver transplantation (OLT), much attention has been paid to its diabetogenic effects. Currently, there are no data on the long term effects of FK-506 in glucose metabolism after OLT. In the present study, we determined the need for outpatient insulin in 52 American veterans who received 58 liver transplants using primary immunosuppression with FK-506 and PRED, with a mean follow-up of 467 days (range 17-952 days). We also analyzed their plasma glucose and FK-506 levels as well as the doses of PRED and FK-506 that they received at various intervals post-OLT. There were 7/52 (13.6%) patients who required insulin for the first time after OLT. Of these, the number of patients on insulin at 3, 6, and 12 months post-OLT was 5/47 (10.6%), 6/44 (13.6%), and 1/26 (3.8%), with none requiring insulin de novo at 18, 24, and 30 months post-OLT. Three patients required insulin temporarily but subsequently became normoglycemic without additional therapy. The need for insulin was not related to the dose of FK-506 administered nor the plasma level. Patients who required outpatient insulin were receiving higher doses of PRED than those not requiring insulin. The need for insulin did not affect the long-term graft or patient survival. In conclusion, the need for insulin with FK-506 compares favorably to that of previous immunosuppressive regimens, and FK-506 may have a reversible diabetogenic effect that is not dose dependent.

[Are thiazides diabetogenic?]

Thiazide treatment is a first-line choice for hypersensitive patients: Thiazides have a flat dose-response as regards blood pressure, but induce biochemical changes only at higher doses. Given in low doses, which careful monitoring of potassium, thiazides provide adequate control of blood pressure without having any substantial impact on blood glucose. In high doses, thiazides may induce three to six new cases of impaired glucose tolerance per 1,000 patient years. The thiazide-induced changes in blood glucose can be prevented by giving lower doses and correcting hypokalaemia, and can be reversed by stopping the drug. In most diabetics, low doses of thiazides do not seem to diminish control of blood glucose. The well-documented effect of thiazides in reducing cardiovascular morbidity and mortality, their safety and their low price make them an excellent first-line choice for treatment of hypertension.