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OBJECTIVES: There are limited data concerning the assessment of renal function in beta-thalassaemia major, with no study of such involvement in Omani patients. The objective of this study was to establish the pattern of renal glomerular and tubular function using traditional and specific laboratory tests in patients with beta-thalassaemia major. METHODS: This cross-sectional study, from January-July 2008, included 30 patients of the Thalassaemia Clinic at the Royal Hospital, Oman, with transfusion-dependent homozygous beta-thalassaemia major. They included 15 males and 15 females, aged 16-32 years with mean ± standard deviation of 21.23 ± 3.42 years. The medical records were reviewed and renal function states assessed as follows: serum creatinine, estimated glomerular filtration rate (eGFR); urea; phosphate, fractional excretion of filtered sodium (FENa); urine albumin: creatinine index; urine ß2-microglobulin:creatinine index; tubular reabsorption of phosphate (TRP), and tubular maximum phosphate reabsorption (TmP)/GFR. RESULTS: All patients had eGFR >90 ml/min/1.73m(2); serum creatinine <90 µmol/L; serum urea <6.0 mmol/L, and urine albumin:creatinine <2.5 mg/mmol. Only 2 (6.7%) patients had FENa >1% and 3 (10.0%) patients had urine ß2-microglobulin: creatinine >22 µg/mmol. All patients had TRP >0.85, of whom seven (23.3%) patients had values within the range of 0.85-0.95 and 23 (76.7%) had values >0.95. Also, all patients had TmP/GFR >1.0 mmol/L, of whom only one (3.3%) patient had TmP/GFR of 1.0-1.5, and 29 (96.7%) patients had TmP/GFR >1.5 mmol/L. Finally, 24 (80%) patients had serum phosphate >1.4 mmol/L. Linear regression revealed a highly significant correlation between serum phosphate and TmP/GFR (r = 0.904, P < 0.001). CONCLUSION: Renal function, glomerular and tubular, appears to be well preserved in beta-thalassaemia major. Almost all renal function indicators were within the recommended ranges. Raised TmP/GFR and TRP were noted in the majority of patients, reflecting an up-trend in serum phosphate and therefore increasing renal phosphate reabsorption.
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OBJECTIVES: This study aims to assess the usefulness of serum holotranscobalamin (holoTC), the fraction of vitamin B12 that is available for tissue uptake, compared with total vitamin B12 in patients investigated for vitamin B12 disorders. METHODS: Serum samples were randomly selected from 76 patients (48 females, 28 males; age range 12-69 years) referred to the Clinical Biochemistry Laboratory, Royal Hospital for the assessment of vitamin B12 status. For each patient, serum total vitamin B12 level was determined by chemiluminescent microparticle immunoassay on Architect 2000 analyzer and holoTC (active vitamin B12) level was determined by microparticle enzyme immunoassay on Axsym analyzer (both from Abbott, USA). RESULTS: Comparison of the data was conducted to reflect the mean, standard deviation (SD) and correlation coefficient between the two groups. The mean (SD) for serum holoTC and total vitamin B12 were 46.5(32.2) pmol/L and 316.3(165.6) pmol/L respectively. There was a significant correlation between holoTC and total vitamin B12 (r= 0.765, P< 0.001) and the regression equation was expressed as; y = a + bx (i.e: holoTC = 1.5 + 0.14 total vitamin B12). Also, the results were assessed for any misclassification when comparing holoTC and the total vitamin B12 in terms of whether each or both values agree or disagree for classifying the patients as having normal or abnormal (low or high) results, based on the cut-off thresholds of the kit's quoted reference range for holo TC of 9 - 123 pmol/L and for total vitamin B12 of 140-600 pmol/L. Accordingly, in 69 (90.8%) samples, there was a parallel agreement/ classification of results, both being normal or abnormal. In 61 (80.4%) patients, both results were normal, whereas in 4 (5.2%) patients, both results were high, and in 4 (5.2%) patients both results were low. However, in 7 (9.8%) cases, there was disagreement/ misclassification of results; 6 (7.8%) patients, holoTC was normal while total vitamin B12 was low, and in 1 (1.4%) patient, holoTC was normal while total vitamin B12 was high. CONCLUSION: It can be recommended that holoTC and total vitamin B12, alone and in combination, have almost equal diagnostic efficiency in screening/diagnosing vitamin B12 deficiency for the majority of patients. In very few patients, holoTC appeared to be a better reflector of vitamin B12 status. Further comparison studies based on a gold standard method for classifying vitamin B12 status are worth considering.
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OBJECTIVES: To assess the pattern of change in serum myoglobin concentration in subjects with thyroid dysfunction. METHODS: Serum samples were selected from 150 subjects with suspected thyroid disorder who were referred to the Royal Hospital, Muscat, Oman. The subjects were 35 males and 115 females, aged 14-56 years with mean ± SD of 34.3 ± 12.7 years. They were classified on the basis of thyroid stimulating hormone (TSH) and free thyroxine (FT4) into 3 groups, each consisting of 50 subjects: hypothyroid, hyperthyroid, and euthyroid subjects. RESULTS: The mean serum myoglobin concentration was higher in hypothyroid patients compared to hyperthyroid and euthyroid subjects (mean ± SD was 38.5 ± 23.1 µg/L in hypothyroid; 18.1 ± 7.0µg/L in hyperthyroid; 17.4 ± 5.7µg/L in euthyroid). There was a significant difference in myoglobin concentration between hypothyroid and euthyroid groups (F = 36.1, p <0.001), however, there was no significant difference between the hyperthyroid and euthyroid groups. When the mean ± 2SD for myoglobin in euthyroid subjects was calculated, the reference range was 6-29 µg/L. Of the hypothyroid subjects, 29 (58%) had high myoglobin and 21 (42%) had normal myoglobin level. No significant correlation was noticed between TSH or FT4 and myoglobin in all studied subjects. CONCLUSION: Raised serum myoglobin may be observed in patients with hypothyroidism. Hence hypothyroidism should be considered in the differential diagnosis of patients with raised serum myoglobin concentration.
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BACKGROUND: Beta-thalassaemia major is a common medical problem worldwide. There is little data dealing with the nature and prevalence of different endocrine disorders in this disease in the Sultanate of Oman. OBJECTIVES: To establish the prevalence and times of occurrence of endocrine disorders in patients with beta-thalassaemia major. METHODS: This cross-sectional study was conducted during Jan-Jul 2008 and dealt with 30 Omani patients with transfusion-dependent homozygous beta-thalassaemia major who were consulting Thalassaemia Clinic, Royal Hospital. They included 15 males and 15 females, aged 16 to 32 years with median of 21 years and mean ± SD of 21.23 ± 3.42 years. The medical records of these patients were reviewed and their endocrine functions were assessed. This assessment included pituitary and gonadal function, thyroid function, bone profile (including Parathyroid Hormone), morning cortisol and fasting glucose. These profiles were reviewed to exclude hypogonadism, hypothyroidism, hypoparathyroidism, hypoadrenalism or diabetes mellitus. RESULTS: Hypogonadism was reported in 22 (73.3%) patients (13 female, 9 male). Low levels of Follicle-Stimulating Hormone (FSH) and low Luteinizing Hormone (LH) with low estradiol (in females) or testosterone (in males) was noted in 15 (50.0%) patients (7 female, 8 male). Normal (but inappropriately low) levels of FSH and LH with low estradiol (in females) or testosterone (in males) was noted in 7 (23.3%) patients (6 female, 1 male). Primary hypothyroidism was present in only 1 (3.3%) patient (female) who Hypoparathyroidism was found in 3 (10.0%) patients (2 female, 1 male). Diabetes mellitus with high fasting glucose was noted in 8 (26.7%) patients (2 female, 6 male). Morning cortisol levels for all patients were within the reference range with no suspicion of hypoadrenal cortical function. Eight (26.7%) patients had no endocrine disorder, 12 (40.0%) patients had one disorder, 8 (26.7%) patients had 2 disorders, and 2 (6.7%) patients had 3 endocrine disorders. There was no significant difference (p>0.050) in mean serum ferritin in thalassaemics with or without endocrinopathy, regardless of the number of endocrinopathy. CONCLUSION: There is high prevalence of endocrine disorders among Omani beta-thalassaemic adult patients. This signifies the importance of awareness for their development and monitoring for early detection and replacement therapy. No relationship between serum ferritin and development of endocrinopathy was noted.
