Normal reference range of serum insulin-like growth factor (IGF)-I in healthy Thai adults.

BACKGROUND: Serum insulin-like growth factor (IGF)-I level is growth hormone (GH) dependent and reflects GH secretion. Analysis of IGF-I is a component in the diagnosis of GH-related disorders and is going to be of interest in determining the risk of many disorders such as cancer or atherosclerosis. The diagnosis value of IGF-I is dependent on the establishment of an accurate reference ranges, which can be affected by parameters such as age, gender, ethnicity, medications, chronic illness, or assay methodologies. OBJECTIVE: To determine reference ranges of IGF-I for healthy Thai adults. MATERIAL AND METHOD: Eight hundred sixteen healthy Thai adults aged between 21-70 years were recruited in the present study. Serum IGF-I was measured by using immunochemiluminescent (ICMA; Roche, USA). Subjects were recorded by their age and gender groups. Data were presented in mean and +/- 2 standard deviation (SD). Correlation analysis between serum IGF-I and physical parameters including sex, age, weight, height, and body mass index (BMI) was also made. RESULTS: The present study demonstrated normal reference range of serum IGF-I by using mean +/- 2 SD value. The well-known age dependency of serum IGF-I levels was also revealed. Levels decreased with increasing age in both genders. The mean value of serum IGF-I was slightly higher in women at the age of 30-40 years compared with men in the same age group, but not statistically insignificant. In addition, serum IGF-I was found to correlate directly with the height and negatively with BMI. However, age-adjusted IGF-I level did not show correlation with these physical parameters. CONCLUSION: This reference range will be beneficial for using IGF-I assay as a tool in the diagnosis of GH function abnormalities in Thai subjects.

Prevalence of adrenal insufficiency in critically ill patients with AIDS.

BACKGROUND: The most common endocrine disorder in patients with human immunodeficiency virus (HIV) is adrenocortical dysfunction. The prevalence of adrenal insufficiency in patients with AIDS is unclear; partly due to different tests, doses of adrenocorticotrophic hormone (ACTH), and criteria used. In addition, there is controversy regarding the assessment of adrenal insufficiency in patients with and without critical illness. OBJECTIVE: To help clarify the prevalence of adrenal insufficiency in patients with AIDS both in critical and non-critical illness, the authors compared the prevalence based on the high-dose ACTH stimulation test. MATERIAL AND METHOD: There were 26 patients with AIDS (19 males and 7 females) with a mean age of 33.6 years (range: 22-46 years). Twelve and 14 patients were in critical and non-critical illness, respectively. RESULT: Overall, the prevalence of adrenal insufficiency was 19.2% (5 of 26) and 30.8% (8 of 26) when a peak stimulated cortisol level of < 18 microg/dL and < 25 microg/dL was defined, respectively. The prevalence was 8.3% and 28.6% in critically and non-critically ill patients; respectively, when a peak stimulated cortisol level of < 18 microg/dL was defined. Finally, when a peak stimulated cortisol level of < 25 microg/dL was defined, the prevalence was 16.7% and 42.9% in critically and non-critically ill patients, respectively. CONCLUSION: Adrenal insufficiency in patients with AIDS is more prevalent than those without HIV infection, no matter what criteria of cortisol response after ACTH test are defined An adrenal testing should be performed in all hospitalized patients with AIDS, both in critical and non-critical illness.

A SPINK1 gene mutation in a Thai patient with fibrocalculous pancreatic diabetes.

Fibrocalculous pancreatitis diabetes (FCPD), a late stage of tropical chronic pancreatitis (TCP), is classified as a secondary cause of diabetes mellitus resulting from pancreatic exocrine dysfunction. The distinctive features of FCPD and TCP are young age at onset, presence of large intraductal pancreatic calculi, and reported mainly in tropical developing countries. Their etiology is still obscure, but the autodigestion due to aberrant intraductal activation of zymogens by trypsin is thought to be a primary common event. Recently, mutations in SPINKI gene encoding a pancreatic secretory trypsin inhibitor have been reported in association with an increased risk of pancreatitis. We describe a heterozygous mutation, IVS3+2 T>C, of SPINK1 gene in a young Thai female patient with typical presentation of FCPD. To our knowledge, this is the first report of the SPINK1 gene mutation in a FCPD patient in Southeast Asia.

A more appropriate algorithm of thyroid function test in diagnosis of hyperthyroidism for Thai patients.

BACKGROUND: Thyroid function test is an essential tool in the diagnosis of thyroid dysfunction. To date, it is still controversial which diagnostic algorithm is best applicable to clinically hyperthyroidism patients. OBJECTIVE: To compare various algorithms of thyroid function tests in the diagnosis of hyperthyroidism. METHOD: Patients from the endocrine clinic, King Chulalongkorn Memorial Hospital were investigated for thyroid function tests (T3, T4, FT3, FT4 and TSH). Hyperthyroidism was defined as an elevated either FT3 or FT4 with suppressed TSH. The authors compared the effectiveness in hyperthyroidism diagnosis among algorithms by using sensitivity, specificity, positive predictive value and negative predictive value. RESULTS: Of all 452 patients in the present study, 94.24 percent were women. There were 206 hyperthyroidism, 30 subclinical hyperthyroidism, 1 subclinical hypothyroidism, 8 primary hypothyroidism and 207 normal subjects. The incidence of T3 toxicosis was 16.02% while that of T4 toxicosis was 2.16%. After the effectiveness analysis of these algorithms, FT3 and TSH is the most optimal test with 97.57% sensitivity and 100% specificity. Compared to FT4 and TSH, it gave 83.98% sensitivity and 100% specificity. CONCLUSION: According to the high incidence of T3 toxicosis in the present study, FT3 and TSH should be the initial test for diagnosis of hyperthyroid patients in an outpatient setting and FT4 should be measured subsequently in case of suspected T4 toxicosis.

A RET C634R mutation in a Thai female with multiple endocrine neoplasia type 2A.

Multiple endocrine neoplasia type 2A (MEN 2A) is an autosomal dominant disorder characterized by medullary thyroid carcinoma, pheochromocytoma and primary hyperparathyroidism. The first tumor is usually a medullary thyroid carcinoma. MEN 2A is caused by mutations in the RET proto-oncogene. The detection of mutations in the gene has important diagnostic and therapeutic impacts. Genetic testing of at-risk family members allows one to identify individuals carrying the mutant alleles with very high specificity and sensitivity. Subsequently, total thyroidectomy, recommended at 5 years of age, can be performed in a prophylactic attempt. The authors performed a molecular analysis to identify a mutation in a Thai woman with MEN 2A. She was found to be heterozygous for 1900T>C (C634R). The patient had two daughters who were not found to carry the mutation. The newly available genetic test for patients with MEN 2A in Thailand makes possible accurate DNA-based diagnosis of their at-risk family members before development of the disease, which has important therapeutic impacts for them.