Biomedical subjects

Rajata Rajatanavin

Publications and source records attributed to Rajata Rajatanavin.

32 records · Page 2Linked to original sources

PubMed2003

The implication of assessing a polymorphism in estrogen receptor alpha gene in the risk assessment of osteoporosis using a screening tool for osteoporosis in Asians.

Both genetic and environmental factors interact to determine bone mass and the risk for developing postmenopausal osteoporosis. Recently, an Asian-specific tool, the Osteoporosis Self-Assessment Tool for Asians (OSTA), has been developed to assess the risk of osteoporosis in women. An index is calculated by multiplying the difference in body weight in kilograms and age in years by 0.2 and disregarding the decimal digits. The risk of osteoporosis is classified as high, intermediate or low according to the OSTA index less than -4, -4 to -1 and greater than -1. In the present study we examined how a single nucleotide polymorphism (SNP) in exon 8 of the estrogen receptor alpha (ERalpha) gene affected the predictive value of the OSTA index. Subjects consisted of 358 postmenopausal women who were at least 55 years old. BMDs were measured by DXA, and the SNP in the ERalpha gene was assessed by PCR-RFLP. When considering both the OSTA index and ERalpha genotype in a logistic regression model, it was found that both the OSTA index and the ERalpha genotype independently contributed to the risk of osteoporosis. The odds ratios were 1.58 (95% CI 1.26-1.91) and 2.51 (95% CI 1.42-4.44) for one unit decrement in the OSTA index and each copy of the A allele of the ERalpha genotype, respectively. The joint effect conformed more to a multiplicative model of interaction than an additive model. This suggests that persons with the high-risk genotype are at far greater risk of developing osteoporosis with advancing age or decreasing body weight, the two variables from which the OSTA index is derived. Targeting preventive measures for osteoporosis subjects with risk factors and also disease-susceptibility alleles is likely to be more cost effective.

Aged↗

PubMed2003

Effect of alendronate on bone mineral density and bone turnover in Thai postmenopausal osteoporosis.

Alendronate has recently been approved for the prevention and treatment of postmenopausal osteoporosis, and its efficacy has been demonstrated in many Western countries. Our present study was performed to evaluate the effect of alendronate on bone mineral density (BMD) and its tolerability in Thais. Eighty postmenopausal women with osteoporosis participated in this study. After giving informed consent, the subjects were randomly allocated either 10 mg alendronate or placebo in a double-blind fashion. All patients received a supplement of 500 mg elemental calcium daily. BMD at the lumbar spine, femoral neck, and distal forearm was measured at baseline and 6 and 12 months after treatment. Biochemical markers of bone resorption were determined at baseline and 6 months after treatment. Baseline characteristics were similar in both alendronate- and placebo-treated groups. Ten subjects discontinued the study. Of 70 subjects, 32 received 10 mg alendronate daily and the remaining subjects received placebo. At 1 year, BMD in the alendronate-treated group had increased from baseline by 9.2%, 4.6%, and 3.1% at lumbar spine, femoral neck, and distal forearm, respectively. These percentages were greater than those in controls (4.1%, 0.6%, and 1.0%, respectively). Urinary N-terminal telopeptide (NTx)-I and serum C-terminal telopeptide (CTx)-I levels decreased in both groups after 6 months of treatment. However, more reduction was demonstrated in the alendronate-treated group (71.9% vs. 28.4%, P < 0.01, and 84.7% vs. 33.1%, P < 0.01, respectively). Compliance with treatment and drug tolerability were good in both alendronate and placebo groups. We concluded that treatment with alendronate 10 mg daily for Thai postmenopausal women with osteoporosis significantly increased BMD at all skeletal sites and reduced biochemical markers of bone resorption. It was well tolerated without any serious side effects.

Aged↗

PubMed2003

Bone mineral density, biochemical and hormonal profiles in suboptimally treated children and adolescents with beta-thalassaemia disease.

OBJECTIVE: Thalassaemia/haemoglobinopathy is a hereditary disease causing increased erythropoiesis and expansion of the bone marrow cavity. As a consequence, there is a reduction in trabecular bone tissue resulting in osteopenia/osteoporosis. The present study was performed to assess bone mineral density (BMD) in children and adolescents with beta-thalassaemia disease and to determine biochemical and hormonal changes that may affect BMD. METHODS: Forty-eight children and adolescents with beta-thalassaemia were divided into two groups, transfusion-dependent (TD) (n = 16) and transfusion-independent (TI) (n = 32). All patients were treated suboptimally. BMD was determined by dual-energy X-ray absorptiometry. Bone maturation was assessed by radiographic bone age (BA). Blood and urine samples were obtained for the determination of biochemical and hormonal profiles, which included PTH, 25-hydroxyvitamin D (25-OHD), osteocalcin, bone-specific alkaline phosphatase, IGF-1, fT4, TSH and urine deoxypyridinoline. RESULTS: Most of the patients were short and underweight, and they had delayed BA with mean Z-scores of -2.77 in the TD and -2.04 in TI groups. The mean Z-scores of BMD in the TD vs. TI groups of total body, radius, femoral neck and lumbar spine were -2.09 vs.-1.49, -0.73 vs. -0.54, -1.93 vs.-1.17 and -3.45 vs.-2.43, respectively. Although the means BMD values in the TD group were lower than those in the TI group, they were not significantly different. Mean serum IGF-1 levels were lower in the TD than the TI groups, 11.6 and 24.9 nmol/l, respectively (P < 0.05). Other biochemical and hormonal profiles did not differ between these two groups. CONCLUSIONS: Patients with undertransfused severe beta-thalassaemia had more bone marrow expansion, lower serum IGF-1 levels and more delayed bone age than did patients with untransfused moderately severe beta-thalassaemia. Therefore, the severity of the disease appeared to be a primary factor for low bone mineral density in undertransfused patients in association with bone age delay and low serum IGF-1.

25-Hydroxyvitamin D 2↗

PubMed2003

Bone histomorphometry in children and adolescents with beta-thalassemia disease: iron-associated focal osteomalacia.

Thalassemia/hemoglobinopathy is a hereditary disease that causes chronic anemia and increased erythropoiesis. Consequently, an expansion of bone marrow spaces may contribute to osteopenia/osteoporosis. However, the pathogenesis of bone changes is not yet known. We, therefore, carried out the study on bone histomorphometry and biochemical and hormonal profiles in children and adolescents with suboptimally treated beta-thalassemia disease with the hope of gaining some new insight into the cellular and structural alterations of thalassemic bone. Seventeen patients underwent iliac crest bone biopsy for histomorphometric analyses. Bone mineral density (BMD) measurements were performed by dual energy x-ray absorptiometry. Most patients had growth retardation and delayed bone age. BMD was low especially at the lumbar spine. Serum IGF-I levels were almost always low. Bone histomorphometry revealed increased osteoid thickness, osteoid maturation time, and mineralization lag time, which indicate impaired bone matrix maturation and defective mineralization. In addition, iron deposits appeared along mineralization fronts and osteoid surfaces. Moreover, focal thickened osteoid seams were found together with focal iron deposits. Dynamic bone formation study revealed reduced bone formation rate. These findings indicate that delayed bone maturation and focal osteomalacia are the pathogenesis of bone disease in suboptimally blood-transfused thalassemics with iron overload. Iron deposits in bone and low circulating IGF-I levels may partly contribute to the above findings.

Adipose Tissue↗

PubMed2003

Abnormalities in bone mineral density and bone histology in thalassemia.

UNLABELLED: This study demonstrated that there was extensive iron staining on trabecular surface and marked reduction in trabecular bone volume without significant alteration in bone formation and bone resorption rates as well as significant reduction in bone mineral density in 18 thalassemic patients. Serum IGF-I was reduced and may modulate the reduction of bone mass. INTRODUCTION: Bone histomorphometric studies in thalassemia to show alterations in bone histology and their relationship to biochemical parameters are very limited. Therefore, this study was systematically conducted to determine the alterations in thalassemia patients. METHODS: Serum biochemical parameters, trans-iliac crest bone biopsy, and determination of bone mineral density of femur and lumbar spine were done in 18 thalassemic patients (10 females and 8 males). RESULTS: Serum osteocalcin, carboxy terminal teleopeptide fragment of type I collagen, and parathyroid hormone levels were within normal limits, but serum 25(OH) vitamin D (19.3 +/- 1.6 ng/ml) and 1,25(OH)2 vitamin D (33.77 +/- 1.51 pg/ml) levels were decreased. Serum insulin-like growth factor I (IGF-I; 145.2 +/- 20 ng/ml) was suppressed, whereas serum ferritin (1366.6 +/- 253.9 ng/ml) was markedly elevated. Reduced bone mineral density was found in all studied areas. Trabecular bone volume was significantly decreased (16.65 +/- 1.12%), whereas bone formation rate, eroded surface, and other bone histomorphometric parameters were within normal limits. The trabecular bone volume varied significantly with bone mineral density of total femur (r = 0.48, p = 0.04). There was an extensive stainable iron surface on the mineral front (9-60%). Significant correlation between serum IGF-I, serum ferritin, stainable iron surface, and bone mineral density, lumbar spine, and total femur were found. Serum IGF-I correlated with trabecular bone volume (r = 0.6, p = 0.03), inversely with both serum ferritin level (r = -0.6, p < 0.01), and inversely with stainable iron surface (r = -0.53, p = 0.02). Multiple regression analysis demonstrated that IGF-I was the only independent variable that determined bone mineral density of lumbar spine and total femur. CONCLUSION: Low bone mineral density and reduced trabecular bone volume with extensive iron deposition are the predominant findings in thalassemic patients. There was no evidence of increased bone resorption or mineralization defect. A reduction in circulatory IGF-I may modulate the reduction of bone mass.

Adult↗

PubMed2002

Risk of calcium oxalate nephrolithiasis in postmenopausal women supplemented with calcium or combined calcium and estrogen.

BACKGROUND: Recent studies showed that postmenopausal women lost less bone mass when supplemented with calcium or estrogen therapy. However, the safety of the treatments in terms of the risk of calcium oxalate stone formation is unknown. We therefore conducted this study to determine the alteration in calcium oxalate supersaturation after calcium supplement or after combined calcium and estrogen therapy in postmenopausal osteoporotic women. METHODS: Fifty-six postmenopausal women were enrolled in this study. All subjects were more than 10 years postmenopausal with vertebral or femoral osteoporosis by bone mineral density criteria. They were randomly allocated to receive either 625 mg of calcium carbonate (250 mg of elemental calcium) at the end of a meal three times a day (group A, n=26) or calcium carbonate in the same manner plus 0.625 mg/day of conjugated equine estrogen and 5 mg medrogestone acetate from day 1-12 each month (group B, n=30). The age (mean +/- S.E.M.) was 66.3 +/- 1.2 and 65.1 +/- 1.1 years, weight 54.1 +/- 1.2 and 55.3 +/- 2.1 kg, in group A and group B, respectively. Urine specimens (24-h) were collected at baseline and 3 months after treatment for the determination of calcium oxalate saturation by using Tiselius's index (AP(CaOx)) and calcium/citrate ratio. RESULTS: After 3 months of treatment, there was no significant alteration from baseline for urinary excretion of calcium, citrate and oxalate. Urinary phosphate excretion was significantly reduced (6.3 +/- 0.7 vs. 5.1 +/- 0.7 mmol/day for group A and 8.2 +/- 0.9 vs. 5.8 +/- 0.7 mmol/day for group B, P<0.05), whereas net alkaline absorption was significantly elevated (10.1 +/- 3.6 vs. 20.1 +/- 4.4 meq/day for group A and 4.8 +/- 3.2 vs. 19.9 +/- 3.6 meq/day for group B, P<0.05). Calcium/citrate ratio and AP(CaOx) determined at baseline were not different from the corresponding values after treatment in both groups; calcium/citrate: 10.1 +/- 3.1 vs. 10.1 +/- 2.5 for group A and 9.3 +/- 1.8 vs. 11.9 +/- 2.5 for group B and AP(CaOx): 1.1 +/- 0.1 vs. 1.3 +/- 0.2 for group A and 1.2 +/- 0.2 vs. 1.1 +/- 0.1 for group B. There were eight and nine patients with high AP(CaOx), or >2, at baseline and after treatment, respectively. CONCLUSIONS: Calcium supplement with a meal or combined calcium supplement and estrogen therapy is not associated with a significant increased risk of calcium oxalate stone formation in the majority of postmenopausal osteoporotic patients. Determination of urinary saturation for calcium oxalate after calcium and estrogen supplements, especially at the initial phase of treatment, may be helpful in the avoidance of nephrolithiasis.

Aged↗

PubMed2002

Bone histology and bone mineral density after correction of acidosis in distal renal tubular acidosis.

BACKGROUND: The association between chronic metabolic acidosis and alterations in bone cell functions has been demonstrated in vitro and in animal studies. However, the causal role of acidosis and the effects of alkaline therapy on bone histology and bone mineral density in chronic metabolic acidosis have never been systematically demonstrated in humans. This study was conducted to examine the alterations in bone mineral density and bone histology before and after correction of acidosis among patients with distal renal tubular acidosis (dRTA) METHODS: Correction of metabolic acidosis by potassium citrate was done in non-azotemic dRTA patients, 6 females and 4 males, who had never received long-term alkaline therapy before enrolling into this study. Blood chemistries, serum intact parathyroid hormone, and 24-hour urine collection for the determination of urinary calcium, phosphate, sodium, potassium, bone mineral density determination, and transiliac bone biopsy were done in all patients at baseline and after one year of potassium citrate therapy. RESULTS: Significant elevations in serum bicarbonate (16.5 +/- 3.0 vs. 24.6 +/- 2.8 mEq/L, P < 0.05) and urinary potassium excretion (35.2 +/- 7.9 vs. 55.4 +/-3.5 mEq/L, P < 0.05) were observed after potassium citrate therapy. No significant alterations in other serum and urine electrolytes were found after the therapy. Serum intact parathyroid hormone level was also significantly elevated after one year of treatment (12.8 +/- 7.3 vs. 26.2 +/- 8.7 pg/mL, P < 0.05). Bone formation rate was significantly suppressed at baseline and was normalized by the treatment (0.02 +/- 0.02 vs. 0.06 +/- 0.03 microm(3)/microm(2)/day, P < 0.05). There were non-significant elevations in trabecular bone volume, osteoblastic and osteoclastic numbers. Bone mineral densities in dRTA patients were also significantly decreased below normal values in most studied areas at baseline and were significantly elevated at the trochanter of femur (0.677 +/- 0.136 vs. 0.748 +/- 0.144 g/c m(2), P < 0.05) and total femur (0.898 +/- 0.166 vs. 0.976 +/- 0.154 g/c m(2), P < 0.05) after the treatment. CONCLUSIONS: This study demonstrates that alkaline therapy corrects abnormal bone cell function and elevates bone mineral density in dRTA patients, indicating the causal role of acidosis in the alterations of bone cell functions and reduction in bone mineral density. Parathyroid gland activity also may be involved in the adaptation of the body to chronic metabolic acidosis.

Acidosis, Renal Tubular↗

PubMed2002

Bone mineral density in rural Thai adults living in Khon Kaen province.

OBJECTIVES: To define the bone status and pattern of bone loss in a normal adult population living in a rural area of Khon Kaen province. STUDY DESIGN: A descriptive study. SETTINGS: Department of Medicine, Faculty of Medicine, Khon Kaen University, Thailand. Subjects 436 subjects (181 men and 255 women), aged 20-80 years. MAIN OUTCOME MEASURES: Bone parameter including total bone mineral density (BMD), the bone mineral density at different sites such as forearm, lumbar spine and hip, bone mineral content (BMC) were measured by dual energy X-ray absorptiometry (DEXA). RESULTS: The result revealed that women had lower bone mass at various bone sites than men. The peak bone mass in women was observed between 30-39 years of age except at the distal radius which occurred between 20-29 years of age while the peak bone mass in men was observed between 20-29 years of age. It was also shown that bone loss occurred in both men and women with advancing age. The rate of decline at all sites in women was greater than men especially when they were over 60 years old. When comparisons were made between pre and post-menopausal women, the mean of bone mineral density in pre-menopausal women was 1.18 +/- 0.08, 0.69 +/- 0.06, 0.69 +/- 0.06, 1.0 +/- 0.13, 1.15 +/- 0.13 g/cm2 at total body, mid-shaft radius, ultra distal radius, femoral neck and lumbar spine, respectively while the mean of bone mineral density in post-menopausal women was 1.02 +/- 0.12, 0.54 +/- 0.11, 0.54 +/- 0.11, 0.75 +/- 0.16, 0.88 +/- 0.2 g/cm2 at total body, mid-shaft radius, ultra distal radius, femoral neck and lumbar spine, respectively which were lower than BMD in pre-menopausal women (p<0.05). The mean bone mineral content (BMC) in pre-menopausal women was 2401+318.3 g while in post-menopausal women it was 1915.4+421.7 g (p<0.05). The rate of bone loss correlated with the duration after menopause. In this study, using World Health Organization criteria for diagnosis of osteopenia and osteoporosis and a reference value obtained from Khon Kaen young adults, the prevalence of osteopenia in Khon Kaen women subjects was 37.4 per cent at femoral neck, 30.2 per cent at lumbar spine, 44.5 per cent at ultra distal radius, 31.5 per cent at mid-shaft radius and the prevalence of was osteoporosis 19.3 per cent at femoral neck, 24.7 per cent at lumbar spine, 18.5 per cent at ultra distal radius and 26.4 per cent at mid-shaft radius. CONCLUSION: The result of this study demonstrated the bone parameters in rural Thai adults living in Khon Kaen province, the pattern of bone loss, the difference between men and women and finally the prevalence of osteopenia and osteoporosis.

Absorptiometry, Photon↗

PubMed2002

Incidence of hip fracture in Chiang Mai.

The reported incidence of hip fracture varies to a large extent across regions. Most studies relied on hospital data under the assumption that nearly all cases of hip fracture get access to hospital care. As in many developing countries, a number of hip fracture cases in Thailand might not seek care in hospitals due to geographical, socio-cultural and financial barriers. Therefore, using hospital data alone, could lead to under estimation of the magnitude of hip fracture. This study was undertaken to obtain such information using a combined method of hospital discharge survey and a cross sectional community survey. It resulted in an estimated incidence of 151.2 per 100,000 (95% CI 136.7-167.2) from the hospital survey and 185.2 per 100,000 (95% CI 138.1-247.6) from the community survey. In comparison to developed countries, age-adjusted incidence of hip fracture in this study was markedly lower than that reported from developed countries. It was argued that different degree of urbanization might explain the discrepancy. This implicated promotion of physical activity as a public health measure to prevent hip fracture.

Aged↗

PubMed2002

Difference in goiter rates between two areas in Mae Hong Son Province despite an equally sufficient iodine supply.

The study was designed to investigate the problem of endemic goiter and iodine supplementation in Mae Hong Son, Thailand. Routine school data still showed high goiter rates in many areas. Six such schools and five schools with declining prevalence of goiter were selected. A single examiner examined all the children. Their weight, height, body mass index, ethnicity, history of iodine intake and migration were recorded. Urine samples were collected for measuring iodine and thiocyanate levels. From 653 children, 105 and 13 were found to have grade 1 and 2 goiter status, respectively. Median values of urine iodine level in children from all schools suggested sufficient iodine supplementation. Multivariate analysis showed that hilltribe minorities had a 2.09 times higher risk of endemic goiter than Thai children. Urine thiocyanate levels among children from high prevalence schools were significantly higher than those from low prevalence schools. No other significant correlation was found. Possible roles of other known and unknown goitrogens should also be investigated.

Child↗

PubMed2002

Influence of normal ageing on mechanism of bone loss in women and men in Bangkok.

UNLABELLED: Age and sex related changes in bone metabolism are of interest in the pathogenesis of osteoporosis. However, most data in the literature were studied in Western countries. In a tropical country, such as Thailand, little is known of vitamin D status and bone remodeling. Thus, the aim of this study was to determine the changes of vitamin D levels and biochemical markers of bone turnover in healthy women and men of various age groups between 20-80 years who were living in Bangkok. From the results, vitamin D levels of various age groups did not alter significantly between men and women except in the sixth decade of women. However, men had higher levels of vitamin D than women. In women, all biochemical markers of bone turnover increased with age, with a sharp increase at the onset of menopause. In contrast, biochemical markers of bone turnover in men gradually declined with advancing age. CONCLUSION: There was no evidence of vitamin D deficiency in the Bangkok population. Women and men showed different age-related changes in bone metabolism.

Adult↗

PubMed2002

Earlier onset of pubertal maturation in Thai girls.

BACKGROUND: Recent studies in the USA and Hong Kong demonstrated the onset of puberty in girls has shifted toward a younger age. Based upon previous studies on variations of pubertal maturation in Thai girls, the secular trend has also moved toward an earlier age. The latest study in 1995 revealed the mean age of menarche was 12.3 years. OBJECTIVES: To identify the onset of puberty, menarche and pubarche in female children and adolescents in 2 Bangkok schools. METHOD: Three hundred school girls aged 9-19 years were enrolled in the study. Data were collected from January 1997 through December 1999. Assessment of pubertal staging by Tanner's criteria was performed by a trained pediatrician. All were in good physical health and had normal height and weight. The median ages of thelarche, menarche and pubarche were estimated by probit analysis. All other parameters were expressed as mean +/- SD. RESULTS: The median ages of thelarche and pubarche were 9.4 and 11.1 years, respectively. Two hundred and twenty one girls had experienced menstruation. The median age of menarche was 11.2 years, whereas, the mean age was 12.1 years. Most girls reached near final adult height after 14 years old. CONCLUSION: The secular trend in decline of the ages of thelarche (or puberty) and menarche was observed in Bangkok girls. Further study in a larger population including a younger age group is required to define the current reference interval of onset of puberty.

Adolescent↗

PubMedDate not supplied

Bone mineral density in children and young adults with beta-thalassemia trait.

BACKGROUND: Homozygous beta-thalassemia is a hereditary hematological disease due to defective beta-globin synthesis. Consequently, there is ineffective erythropoiesis and increased peripheral hemolysis. Increased erythropoiesis in bone marrow results in expansion of marrow cavity and reduced bone mass. Patients with heterozygous beta-thalassemia or beta-thalassemia trait may have mild anemia, and consequently mildly increased erythropoiesis. Whether modestly increased erythropoiesis might decrease bone mass is not well established. OBJECTIVE: To evaluate bone mineral density (BMD) in children and young adults with beta-thalassemia trait. METHODS: Thirty-one healthy young adults aged 20-45 yr and 26 healthy children aged 8-15 yr with beta-thalassemia trait were enrolled in the study. BMD was determined by dual X-ray absorptiometry (DEXA). Determinations of intact parathormone (PTH), 25-hydroxyvitamin D (25-OHD), and bone markers were performed. RESULTS: In adults, all had z-scores of BMD more than -2 above the mean. The mean z-scores of BMD of lumbar spine, radius and femoral neck were 0.11, -0.10 and 0.41, respectively. In children, only two of 26 had z-scores of lumbar spine BMD more than -2 below the mean. The mean z-scores of BMD of total body, lumbar spine, radius and femoral neck were 0.12, -0.28, 0.30 and -0.14, respectively. All subjects had normal PTH, 25-OHD and bone markers levels. CONCLUSION: beta-Thalassemia trait is not a contributing factor for osteopenia/osteoporosis in children and young adults.

Adolescent↗

PubMedDate not supplied

Propylthiouracil-induced sensorineural hearing loss associated with antineutrophil cytoplasmic antibodies.

OBJECTIVE: To report the case of a young woman with Graves' disease in whom ototoxicity developed because of propylthiouracil (PTU)-induced antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. METHODS: We present the clinical findings, pertinent laboratory data, and follow-up course of a patient with Graves' disease and bilateral sensorineural hearing loss. We also provide a literature review regarding thionamide-induced ANCA-associated vasculitis. RESULTS: In a 22-year-old Thai woman with Graves' disease, tinnitus, hearing impairment in the left ear (with progression to the right ear), and vertigo developed after 3 years of therapy with PTU. Audiograms showed bilateral sensorineural hearing loss with cochlear lesions. She also had low-grade fever, intermittent chronic abdominal pain, weight loss, polyarthralgia, and conjunctivitis. An indirect immunofluorescence test for ANCA was positive. The hearing impairment and tinnitus were gradually reduced after PTU withdrawal and corticosteroid and azathioprine treatment. Definitive therapy by subtotal thyroidectomy was subsequently performed and yielded good results. CONCLUSION: This rare case of PTU-induced ANCA-associated vasculitis manifested with ototoxicity in combination with systemic involvement.

Adrenal Cortex Hormones↗