Diabetes after aerosolized pentamidine

Glucose disorders associated with HIV and its drug therapy

OBJECTIVE

To review the impact that factors such as HIV infection, antiretrovirals, and other commonly used drug therapies have on glucose metabolism in HIV-infected patients.

DATA SOURCES

Pertinent literature was identified via a MEDLINE search from 1980 to April 2000 and through secondary sources (abstracts presented at recent scientific meetings, manufacturers' package inserts). The key words used were antiretroviral therapy, HIV infection, insulin resistance, and metabolic abnormalities. All information deemed relevant to evaluate the impact that HIV infection and drug therapy have on glucose metabolism in HIV-infected patients was included.

DATA SYNTHESIS

The viral burden and stress that are present in HIV-infected patients elicit a complex hormonal and immunologic response that may alter various biochemical pathways, including glucose metabolism. Although rare before the era of potent antiretroviral therapy, insulin resistance has now been described as an important component of the lipodystrophy syndrome. The complex and multifactorial nature of glucose metabolism dysregulation makes management of hyperglycemia or diabetes mellitus challenging in HIV-infected patients. In such a context, a set of recommendations was developed to guide practitioners in assessing, treating, and monitoring hyperglycemia or diabetes mellitus in HIV-infected patients.

CONCLUSIONS

Alterations of glucose metabolism observed in HIV-infected patients are more frequent since the introduction of potent antiretroviral therapy. Although the etiology of such abnormalities remains unknown, protease inhibitors and, to a lesser extent, nucleoside reverse transcriptase inhibitors are believed to participate in their pathogenic mechanisms. Because of similarities to the pathogenesis of diabetes mellitus, management of antiretroviral-induced hyperglycemia could follow that the recommendations of the American Diabetes Association, with special considerations for monitoring patients with HIV infection. Future studies of altered glucose metabolism in HIV-infected patients should focus on understanding the precise mechanism or causes of this complication so that preventive and therapeutic guidelines can be further evaluated.

Disorders of glucose metabolism in patients infected with human immunodeficiency virus

New-onset diabetes mellitus, clinically similar to type 2 diabetes, will affect a small proportion (1%-6%) of patients infected with human immunodeficiency virus (HIV) who are treated with HIV-1 protease inhibitors (PIs). However, insulin resistance and impaired glucose tolerance will develop during PI treatment in a considerable proportion of patients. Dyslipidemia, abdominal obesity, and loss of peripheral fat frequently coexist with insulin resistance, but it is not clear whether all of these result from a common pathogenic mechanism. Recent data suggest that insulin resistance may also be associated with HIV infection in patients not receiving PI therapy. The long-term consequences of insulin resistance in this population are not known. The effect of switching to other antiretroviral therapies has not been fully determined. Treatment of established diabetes mellitus should generally follow existing guidelines. There is no clinically useful screening test that will determine the existence and degree of insulin resistance in individual patients. It is therefore reasonable to recommend general measures to increase insulin sensitivity in all patients infected with HIV, such as weight reduction for obese persons and regular aerobic exercise.

Severe hyperglycemia in an HIV clinic: preexisting versus drug-associated diabetes mellitus

We determined the frequency and clinical nature of severe hyperglycemia in a university clinic for HIV-1-infected patients. The medical records of 1392 adult HIV-infected patients were reviewed for cases of severe hyperglycemia, defined as two or more serum glucose values >250 mg/dl or diabetes treatment during clinic care. Demographic information, family histories of diabetes mellitus, body weights, CD4+ lymphocyte counts, and use of corticosteroids, megestrol acetate, pentamidine, or didanosine were recorded for subjects meeting the case definition. Comparisons were made between preexisting diabetic (group 1) and incident hyperglycemic cases (group 2). Less than 2% of the total clinic population experienced severe hyperglycemia: 12 in group 1 and 13 in group 2. Group 2 had lower body weights (mean, 70.6 kg versus 90.0 kg; p < 0.05) and more advanced HIV disease (mean CD4 count, 79/mm3 versus 550/mm3; p < 0.05) than group 1. Group 2 cases had evidence of drug-associated hyperglycemia; four cases demonstrated hyperglycemia coinciding with large fluctuations in weight during megestrol therapy. Among megestrol recipients, cases did not differ from noncases in demographics, weight, or CD4 count. Severe hyperglycemia is uncommon in adult HIV-infected patients. Approximately one half of these patients have preexisting diabetic conditions; many of the remainder may have drug-induced hyperglycemia, especially as a result of corticosteroids or megestrol acetate.

Pancreatic lesions in HIV-infected patients

The pancreas is frequently involved during HIV infection, especially by disseminated infections or neoplasms. These lesions are generally asymptomatic and are discovered at autopsy. However, hypoglycaemia secondary to massive pancreatic infiltration by a tumour or tuberculous necrosis may occur. The most important cause of pancreatic dysfunction in HIV-infected patients is a drug toxic effect (intravenous pentamidine, didanosine, zalcitabine). Hypoglycaemia, which may or may not be followed by diabetes, can develop during intravenous pentamidine therapy. In cases with increased serum amylase and/or lipase levels, potentially toxic drugs must be promptly discontinued to avoid major pancreatic involvement.