Biomedical subjects

S Sethu K Reddy

Publications and source records attributed to S Sethu K Reddy.

6 recordsLinked to original sources

PubMed2006

Endocrinology update 2006.

Endocrinology has recently witnessed several important developments: The Epidemiology of Diabetes Interventions and Complications study, a follow-up to the landmark Diabetes Control and Complications trial, found that strict glucose control early in the course of type 1 diabetes reduces the risk of microvascular and cardiovascular complications and provides prolonged benefits even if intensive control is not so tightly maintained. Inhaled insulin preparations are now available for mealtime coverage. We now have two new injectable medications for diabetes; pramlintide (Symlin) and exenatide (Byetta) are good adjuncts for patients with both type 1 and type 2 diabetes who have trouble reaching their hemoglobin A1c target, and they can help control and even reduce weight. Thyroxine (T4), instead of being merely a "prohormone," has been found to have direct actions on cells, leading to rapid clinical effects and possibly oncogenesis and angiogenesis. The therapeutic range for thyrotropin (TSH) may be much narrower than traditionally believed: some have proposed that the normal range should be redefined as 0.4 to 2.5 mIU/L. New evidence shows that vitamin D is important for more than calcium control and may help prevent type 1 diabetes.

Diabetes Complications↗

PubMed2003

Raloxifene causing malabsorption of levothyroxine.

To our knowledge, raloxifene hydrochloride, a selective estrogen receptor modulator, has never been reported to interfere with absorption of levothyroxine. We describe a 79-year-old woman with chronic, treated primary hypothyroidism, presenting with increasing levothyroxine requirement while taking raloxifene at the same time as levothyroxine. For two 6- to 8-week periods, we separated the ingestion of raloxifene and levothyroxine by about 12 hours. In addition, we tested the absorption of 1.0 mg of levothyroxine sodium with and without the coadministration of 60 mg of raloxifene hydrochloride on 2 separate occasions by collecting serial blood samples for 6 hours. Hypothyroidism occurred in a reproducible fashion whenever levothyroxine and raloxifene were administered together and improved whenever they were taken separately. Combined administration of levothyroxine and raloxifene resulted in lower levels of serum thyroxine compared with administration of levothyroxine alone. By a yet unknown mechanism, raloxifene caused malabsorption of levothyroxine in our patient when coadministered.

Absorption↗

PubMed2002

Basal and postglucagon C-peptide levels in Ethiopians with diabetes.

OBJECTIVE: To study basal C-peptide (BCP) and postglucagon C-peptide (PGCP) levels in Ethiopians with diabetes. RESEARCH DESIGN AND METHODS: A total of 56 subjects with type 1 diabetes, 97 subjects with type 2 diabetes, and 50 control subjects were recruited from a hospital in Ethiopia. BCP was determined in all subjects and PGCP in 86 subjects. RESULTS: Mean (+/- SEM) BCP, PGCP, and the increment after glucagon in type 1 diabetic subjects (0.14 +/- 0.04, 0.22 +/- 0.11, and 0.08 +/- 0.05 nmol/l, respectively) were lower (P < 0.001) than those in type 2 diabetic subjects (0.66 +/- 0.04, 1.25 +/- 0.10, and 0.56 +/- 0.06 nmol/l, respectively) or control subjects (0.54 +/- 0.04, 1.52 +/- 0.26, and 1.11 +/- 0.24 nmol/l, respectively). The mean BCP level was higher in type 2 diabetic subjects than control subjects (P=0.015), whereas the mean increment was lower (P=0.005). Insulin-treated type 2 diabetic subjects, compared with non-insulin-treated type 2 diabetic subjects, had lower mean BCP (0.55 +/- 0.08 nmol/l [n=37] vs. 0.73 +/- 0.04 [n=60], P=0.001), lower PGCP (0.97 +/- 0.20 nmol/l [n=18] vs. 1.40 +/- 0.11 [n=35], P=0.010), and a lower C-peptide increment (0.34 +/- 0.06 [n=18] vs. 0.67 +/- 0.07 nmol/l [n=35], P=0.003). In both the type 1 and type 2 diabetic groups, those with BCP levels <0.2 nmol/l had lower BMI than those with higher BCP levels (P=0.023 and P < 0.001, respectively). CONCLUSIONS: Combined with clinical criteria, C-peptide levels are good discriminators between type 1 and type 2 diabetes in Ethiopians and may also be useful in identifying subjects with type 2 diabetes who require insulin therapy. There is a subgroup of type 2 diabetic subjects with features of type 1 diabetes.

Adult↗

PubMedDate not supplied

Management of nondiagnostic thyroid fine-needle aspiration biopsy: survey of endocrinologists.

OBJECTIVE: To evaluate the approach of endocrinologists in the setting of nondiagnostic thyroid fine-needle aspiration (FNA) biopsies. METHODS: In 2002, we surveyed physicians attending the national annual meetings of the American Association of Clinical Endocrinologists and the Endocrine Society of North America, using a 13-item questionnaire. The responses were tallied and analyzed. RESULTS: Of the 143 respondents, 139 were endocrinologists, with a male:female ratio of 2.5:1. Most respondents were involved in a medical practice in North America, but Europe, Asia, New Zealand, and Australia were also represented. Of those performing thyroid FNA biopsy, 31% used thyroid ultrasound guidance. Among the survey respondents, 16%, 49%, 20%, and 15% performed less than 2, 2 to 5, 6 to 10, and more than 10 thyroid FNA biopsies per month, respectively. Among the respondents, 13.5%, 44%, 28.5%, 10%, and 4% had non-diagnostic rates of less than 5%, 5 to 10%, 11 to 20%, 21 to 30%, and more than 30%, respectively. The approach of the respondents to an initially nondiagnostic FNA was repeated FNA biopsy in 87%, observation in 7%, levothyroxine suppression in 4%, and thyroid scintigraphy in 2%. Respondents believed that the most cost-effective approach in a patient with nondiagnostic FNA was repeated biopsy (82%), monitoring the size of the thyroid nodule (17%), and surgical referral (<1%). No one was willing to repeat the thyroid biopsy more than three times. CONCLUSION: On the basis of findings in our survey, most endocrinologists repeat thyroid FNA at least once when confronted with a nondiagnostic result. No published studies have demonstrated the cost-effectiveness of this approach versus proceeding to surgical intervention or observation. We hope that this survey will encourage further studies on this issue.

Attitude of Health Personnel↗

PubMedDate not supplied

Metastatic malignant insulinoma in a patient with type 2 diabetes mellitus: case presentation and literature review.

OBJECTIVE: To describe the occurrence of metastatic malignant insulinoma in a patient with preexisting type 2 diabetes mellitus. METHODS: We present a detailed case report, with clinical, biochemical, and imaging findings, and summarize the data from 21 similar cases in the literature. RESULTS: The occurrence of malignant insulinoma in a patient with preexisting diabetes is very rare and thus can be a diagnostic challenge. In our patient with type 2 diabetes, endogenous hyperinsulinism was confirmed by demonstrating elevated insulin and C-peptide levels during hypoglycemic episodes in the absence of sulfonylurea on a blood screen. Abdominal computed tomographic scan and magnetic resonance imaging revealed a pancreatic mass as well as metastatic lesions in the liver. The pancreatic mass was removed and confirmed to be a malignant insulinoma. This procedure was followed by disappearance of the hypoglycemic episodes as well as the diabetes for a few months. On follow-up, however, more metastatic lesions appeared in conjunction with a protracted course of hypoglycemia that necessitated treatment with antihypoglycemic agents and, 3 years after the initial surgical intervention, culminated in the death of the patient. CONCLUSION: Our patient is one of the few subjects known to have a malignant insulinoma in conjunction with preexisting diabetes. A high degree of suspicion for the presence of an insulinoma should be maintained when unexplained hypoglycemic episodes occur in a patient with previously stable diabetes.

Adult↗

PubMedDate not supplied

Development of diabetes mellitus several years after manifestation of diabetic nephropathy: case report and review of literature.

OBJECTIVE: To describe an unusual case of development of diabetes mellitus (DM) several years after manifestation of diabetic nephropathy and to review the related literature. METHODS: We present a case report, including detailed laboratory and pathologic findings in a 51-year-old man who was diagnosed as having DM several years after presenting with diabetic nephropathy. The pertinent literature is also reviewed. RESULTS: A 51-year-old African American man presented with proteinuria of 4 g/24 h. Past medical history was significant for impaired glucose tolerance diagnosed 2 years previously. Subsequent follow-up demonstrated fasting blood glucose levels ranging from 108 to 123 mg/dL and glycated hemoglobin levels ranging from 5.3 to 5.8%. The patient also had chronic hepatitis C, hypertension, a history of intravenous drug abuse, and a family history of DM and hypertension. On examination of the patient, his blood pressure was 180/90 mm Hg. Funduscopy revealed mild diabetic retinopathy. Work-up was negative for glomerulonephritis, connective tissue disease, vasculitis, or multiple myeloma. Kidney biopsy revealed thickened glomerular basement membranes and diffuse glomeru-losclerosis, consistent with diabetic nephropathy. During follow-up, 9 years after presenting with proteinuria and 4 years after diagnosis of biopsy-proven diabetic nephropathy, the patient had a blood glucose level of 890 mg/dL and diabetic ketoacidosis. CONCLUSION: This case provides one explanation for the natural course of patients who present with "diabetic complications" but have no diabetes. Some of those patients may have "prediabetes" and may manifest with DM during follow-up. We also conclude that hyperglycemia is not the only important factor in the pathogenesis of diabetic nephropathy.

Blood Glucose↗