Calcium and vitamin D metabolism in acromegaly

1981 ◽  
Vol 96 (4) ◽  
pp. 444-450 ◽  
Author(s):  
Bjarne Lund ◽  
Peter Claes Eskildsen ◽  
Birger Lund ◽  
Anthony W. Norman ◽  
Ole Helmer Sørensen
Keyword(s):  
Growth Hormone ◽  
Serum Concentration ◽  
Urinary Excretion ◽  
Direct Action ◽  
Elevated Serum ◽  
Serum Levels ◽  
Calcium Excretion ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D ◽  
Free Cortisol

Abstract. Acromegalic subjects were found to have elevated serum levels of both 1,25-dihydroxyvitamin D (1,25-(OH)2D), (67 ± 22 (sd) pg/ml) and 24,25-dihydroxyvitamin D (24,25-(OH)2D), (6.9 ± 1.5 (sd) ng/ml). The serum concentration of 1,25-(OH)2D correlated positively (P < 0.02, R = 0.56) to the 24 h urinary excretion of growth hormone, but not to the serum levels of parathyroid hormone, prolactin, thyroid hormones or the urinary excretion of free cortisol. Fourteen patients were treated with bromocriptine at doses from 15–45 mg/day for a period of about 6 months. This was accompanied by a significant decrease in the urinary excretion of growth hormone and calcium and in the serum concentrations of 1,25-(OH)2D and 24,25-(OH)2D. A relationship was demonstrated between the decrease in urinary calcium excretion and the decrease in serum 1,25-(OH)2D (P < 0.02, R = 0.64). It is concluded that the serum concentration of 1,25-(OH)2D is elevated in acromegaly, perhaps as a consequence of a direct action of growth hormone on the renal lα-hydroxylase activity.

Effect of Parathyroid Hormone on cAMP and 1,25-Dihydroxyvitamin D Formation and Renal Handling of Phosphate in Vitamin D-Dependent Rickets

PEDIATRICS ◽  
1983 ◽  
Vol 71 (1) ◽  
pp. 59-63
Author(s):  
Dagfinn Aarskog ◽  
Lage Aksnes ◽  
Trond Markestad
Keyword(s):  
Vitamin D ◽  
Parathyroid Hormone ◽  
Serum Concentration ◽  
Urinary Excretion ◽  
Serum Levels ◽  
Renal Handling ◽  
Hydroxyvitamin D ◽  
Dihydroxyvitamin D ◽  
1,25 Dihydroxyvitamin D ◽  
Control Subjects

Studies were carried out to compare the effects of parathyroid extract (PTE) on the serum concentration of 1,25-dihydroxyvitamin D (1,25[OH]2D), 24,25-dihydroxyvitamin D (24,25[OH]2D), 25,26-dihydroxy vitamin D (25,26[OH]2D) and cAMP, and the urinary excretion of calcium, phosphorus, and cAMP in two normal adult subjects, and in a girl with vitamin D-dependent rickets. The concentration of 1,25[OH]2D was markedly decreased even when she was receiving a daily dose of 25,000 IU of ergocalciferol. PTE infusion resulted in a prompt and distinct increase in the serum levels and the urinary excretion of cAMP in the patient and control subjects. In the control subjects the serum concentration of 1,25[OH]2D increased after the PTE infusion, whereas there was no response in the patient with vitamin D-dependent rickets. The two other dihydroxylated metabolites of vitamin D showed no consistent response to the PTE infusion in the control subjects or the patient. The patient showed no phosphaturic response to PTE while she was receiving high-dosage ergocalciferol treatment. By contrast, when the patient was re-studied after therapy with lα-hydroxyvitamin D, PTE infusion resulted in an increase in urinary phosphate excretion. These findings might lend support for the notion that 1,25[OH]2D has an effect on tubular phosphate resorption and has a permissive role in the phosphaturic effect of parathyroid hormone. The present findings also confirm that the formation of 1,25[OH]2D is impaired in vitamin D-dependent rickets and indicate that the renal 25-hydroxyvitamin D-lα-hydroxylase is unresponsive to the stimulatory effect of parathyroid hormone in this condition.

scholarly journals D-thyroxine reduces lipoprotein(a) serum concentration in dialysis patients.

1998 ◽  
Vol 9 (1) ◽  
pp. 90-96
Author(s):  
C Bommer ◽  
E Werle ◽  
I Walter-Sack ◽  
C Keller ◽  
F Gehlen ◽  
...  
Keyword(s):  
Serum Concentration ◽  
Ldl Cholesterol ◽  
Clinical Symptoms ◽  
Hormone Secretion ◽  
Elevated Serum ◽  
Serum Levels ◽  
Controlled Study ◽  
Dialysis Patients ◽  
Lipoprotein A ◽  
Thyroxine Therapy

Uremia raises lipoprotein(a) (Lp(a)) serum concentration and the risk of arteriosclerosis in dialysis patients. The treatment of high Lp(a) levels is not satisfactory today. The decrease of Lp(a) in hypothyroid patients on L-T4 therapy raised the question of whether dextro-thyroxine (D-thyroxine) reduces not only serum cholesterol, but also Lp(a) serum concentration. In a single-blind placebo-controlled study, the influence of D-thyroxine therapy on Lp(a) serum concentration was evaluated in 30 hemodialysis patients with elevated Lp(a) serum levels. Lp(a) was quantified in parallel by two methods, i.e., rocket immunoelectrophoresis and nephelometry, and apo(a) isoforms were determined by a sensitive immunoblotting technique. Regardless of the apo(a) isoforms, 6 mg/d D-thyroxine reduced elevated Lp(a) levels significantly by 27 +/- 13% in 20 dialysis patients (P < 0.001) compared with 10 control subjects (-9.9 +/- 8.4%). In parallel, D-thyroxine therapy significantly lowered total cholesterol (P < 0.001), LDL cholesterol (P < 0.001), and LDL cholesterol/HDL cholesterol ratio (P < 0.01); raised T4 and T3 serum levels; and suppressed thyroid-stimulating hormone secretion without causing clinical symptoms of hyperthyroidism in any of the patients. D-Thyroxine reduces elevated serum Lp(a) concentration in dialysis patients. The effect in nondialysis patients can be expected but remains to be proven.

Contrasting effects of intravenous and oral etidronate on vitamin D metabolism in man

1988 ◽  
Vol 74 (1) ◽  
pp. 101-106 ◽  
Author(s):  
P. J. Lawson-Matthew ◽  
D. F. Guilland-Cumming ◽  
A. J. P. Yates ◽  
R. G. G. Russell ◽  
J. A. Kanis
Keyword(s):  
Vitamin D ◽  
Urinary Excretion ◽  
Progressive Increase ◽  
Urinary Calcium ◽  
Calcium Excretion ◽  
Vitamin D Metabolism ◽  
Dihydroxyvitamin D3 ◽  
Renal Tubular Reabsorption ◽  
Early Effects ◽  
Renal Tubular

1. We have studied the early effects of intravenously and orally administered etidronate on vitamin D metabolism and indirect indices of calcium and skeletal metabolism in 17 patients with Paget's disease of bone. 2. Administration of etidronate by mouth (700–1400 mg daily for 1 month) or its intravenous infusion (300 mg daily for 5 days) decreased bone resorption as judged by urinary excretion of hydroxyproline and significantly increased renal tubular reabsorption of phosphate. No significant change in serum activity of alkaline phosphatase was noted with either regimen. 3. When etidronate was given by mouth there was a progressive decrease in fasting urinary calcium excretion and a rise in serum 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. In contrast, intravenous etidronate decreased serum values of l,25-(OH)2D3 and was associated with a progressive increase in fasting calcium excretion, suggesting a decrease in the net influx of calcium from the extracellular compartment to bone. Significant inverse correlations were noted between the change induced in 1,25-(OH)2D3 values at 2 weeks and the changes in serum calcium, phosphate and fasting urinary excretion of calcium. 4. These observations suggest that the different effects of intravenous and oral etidronate on l,25-(OH)2D3 values are a consequence of different doses of etidronate used and the different effects of these regimens on the accretion of calcium into bone.

Effects of long-term elevated serum levels of growth hormone on life expectancy of mice: Lessons from transgenic animal models

1993 ◽  
Vol 68 (1-3) ◽  
pp. 71-87 ◽  
Author(s):  
Eckhard Wolf ◽  
Eva Kahnt ◽  
Jörn Ehrlein ◽  
Walter Hermanns ◽  
Gottfried Brem ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Animal Models ◽  
Life Expectancy ◽  
Elevated Serum ◽  
Serum Levels ◽  
Transgenic Animal ◽  
Transgenic Animal Models

Serum and Urinary Levels of Nitric Oxide and Uric Acid in Nigerian Children with Asthma

2021 ◽  
Vol 7 (1) ◽  
pp. 44-48
Author(s):  
Olatunbosun Arinola ◽  
Temiloluwa Olaiya ◽  
Victory Edem ◽  
Sheu Rahamon
Keyword(s):  
Nitric Oxide ◽  
Uric Acid ◽  
Urinary Excretion ◽  
Elevated Serum ◽  
Serum Levels ◽  
Healthy Children ◽  
Urinary Levels ◽  
Children With Asthma ◽  
Concomitant Reduction ◽  
Study Methodology

Background: Asthma is associated with increased production of reactive oxygen and nitrogen species and an alteration in the levels of antioxidants activities in the lung and blood. The increased production of the superoxide anion radicals contributes to airway remodelling and disease severity. Physiologically, the effect of increased free radical generation is eliminated by corresponding activities of a network of antioxidants. Presently, there is the dearth of information on the steady-state concentrations of nitric oxide (NO) and uric acid (UA) in children with asthma. The serum and urinary levels of NO and UA in children with asthma were thus determined in this study. Methodology: Fifty children consisting of 25 children with asthma and 25 age-matched apparently healthy children without asthma were enrolled into this study. Serum and urinary levels of NO and UA were determined using standard methods. Results: Serum levels of NO and UA were significantly higher while the urinary levels of NO and UA were significantly lower in children with asthma compared with the controls. There was no significant correlation between the serum ad urinary levels of NO and UA in children with asthma. Also, gender differences were not observed in the serum and urinary levels of NO and UA in children with asthma. Conclusion: Children with asthma have elevated serum levels of NO and UA accompanied with suboptimal urinary excretion. Therefore, children with asthma might benefit from routine renal function assessment owing to damages that can result from systemic accumulation of UA with concomitant reduction in its urinary excretion.

scholarly journals Increased Circulatory Level of Biologically Active Full-Length FGF-23 in Patients with Hypophosphatemic Rickets/Osteomalacia

2002 ◽  
Vol 87 (11) ◽  
pp. 4957-4960 ◽  
Author(s):  
Yuji Yamazaki ◽  
Ryo Okazaki ◽  
Minako Shibata ◽  
Yukihiro Hasegawa ◽  
Kohei Satoh ◽  
...  
Keyword(s):  
Sandwich Elisa ◽  
Elevated Serum ◽  
Serum Levels ◽  
Biologically Active ◽  
Hypophosphatemic Rickets ◽  
Dihydroxyvitamin D ◽  
Autosomal Dominant Hypophosphatemic Rickets ◽  
Circulatory Level ◽  
Fgf 23

Abstract Hypophosphatemic rickets/osteomalacia with inappropriately low serum 1,25-dihidroxyvitamin D level is commonly observed in X-linked hypophosphatemic rickets/osteomalacia, autosomal dominant hypophosphatemic rickets/osteomalacia and tumor-induced osteomalacia. Although the involvement of a newly identified factor, FGF-23, in the pathogenesis of ADHR and TIO has been suggested, clinical evidence indicating the role of FGF-23 has been lacking. We have previously shown that FGF-23 is cleaved between Arg179 and Ser180, and this processing abolished biological activity of FGF-23 to induce hypophosphatemia. Therefore, sandwich ELISA for biologically active intact human FGF-23 was developed using two kinds of monoclonal antibodies that requires the simultaneous presence of both the N-terminal and C-terminal portion of FGF-23. The serum levels of FGF-23 in healthy adults were measurable and ranged from 8.2 to 54.3 ng/L. In contrast, those in a patient with TIO were over 200 ng/L. After the resection of the responsible tumor, the elevated FGF-23 level returned to normal level within 1 h. The increase of serum concentrations of 1,25-dihidroxyvitamin D and phosphate, and the decrease of serum 24,25-dihydroxyvitamin D followed the change of FGF-23. In addition, the elevated serum FGF-23 levels were demonstrated in most patients with XLH. It is likely that increased serum levels of FGF-23 contributes to the development of hypophosphatemia not only in TIO but also in XLH.

Familial hypocalciuric hypercalcaemia: observations on vitamin D metabolism and parathyroid function

1983 ◽  
Vol 104 (2) ◽  
pp. 210-215 ◽  
Author(s):  
M. Davies ◽  
P. H. Adams ◽  
J. L. Berry ◽  
G. A. Lumb ◽  
P. S. Klimiuk ◽  
...  
Keyword(s):  
Vitamin D ◽  
Serum Concentration ◽  
Primary Hyperparathyroidism ◽  
Calcium Excretion ◽  
Renal Tubules ◽  
Vitamin D Metabolites ◽  
Vitamin D Metabolism ◽  
Hydroxyvitamin D ◽  
25 Hydroxyvitamin D ◽  
Renal Tubular

Abstract. Serum vitamin D metabolites, the renal tubular maximum reabsorptive rate for phosphate (TMP/GFR) nephrogenic cyclic AMP (NcAMPI, and CaE (urinary calcium excretion per litre of glomerular filtrate) were measured in 14 adults with familial hypocalciuric hypercalcaemia (FHH). The findings were compared with analyses in 14 patients with surgically proven primary hyperparathyroidism matched for serum calcium, creatinine clearance and vitamin D status (assessed by serum concentrations of 25 hydroxyvitamin D). Vitamin D metabolites were also measured in 16 normocalcaemic relatives of patients with FHH. The serum concentration of 24, 25 dihydroxycholecalciferol was appropriate for the prevailing 25 hydroxyvitamin D and no difference was found between groups. The serum concentration of 1, 25 dihydroxycholecalciferol was significantly greater in primary hyperparathyroidism (P < 0.0005) compared with patients with FHH and their normocalcaemic relatives. TMP/GFR was reduced in both primary hyperparathyroidism (0.53 ± 0.12 mmol/l GF, mean ± sem) and FHH (0.86 ±0.14 mmol/l GF). Patients with primary hyperparathyroidism showed an increase in NcAMP output in the urine (38.5 ± 16 mmol/l GF) which was significantly greater (P < 0.0001) than the normal NcAMP (13.5 ± 9.2 nmol/l GF) found in FHH. CaE was low in FHH indicating increased renal tubular reabsorption of calcium. It is concluded that there is no abnormality of vitamin D metabolism in FHH comparable with the changes observed in primary hyperparathyroidism. It is suggested that the biochemical abnormalities in FHH cannot be explained solely upon an increased sensitivity of the renal tubules to the effects of endogenous parathyroid hormone.

scholarly journals Rickets guidance: part I—diagnostic workup

2021 ◽  
Author(s):  
Dieter Haffner ◽  
Maren Leifheit-Nestler ◽  
Andrea Grund ◽  
Dirk Schnabel
Keyword(s):  
Vitamin D ◽  
Clinical Symptoms ◽  
Fibroblast Growth Factor 23 ◽  
Correct Diagnosis ◽  
Elevated Serum ◽  
Growth Failure ◽  
Serum Levels ◽  
Calcium Deficiency ◽  
X Rays ◽  
Vitamin D Metabolism

AbstractRickets is a disease of the growing child arising from alterations in calcium and phosphate homeostasis resulting in impaired apoptosis of hypertrophic chondrocytes in the growth plate. Its symptoms depend on the patients’ age, duration of disease, and underlying disorder. Common features include thickened wrists and ankles due to widened metaphyses, growth failure, bone pain, muscle weakness, waddling gait, and leg bowing. Affected infants often show delayed closure of the fontanelles, frontal bossing, and craniotabes. The diagnosis of rickets is based on the presence of these typical clinical symptoms and radiological findings on X-rays of the wrist or knee, showing metaphyseal fraying and widening of growth plates, in conjunction with elevated serum levels of alkaline phosphatase. Nutritional rickets due to vitamin D deficiency and/or dietary calcium deficiency is the most common cause of rickets. Currently, more than 20 acquired or hereditary causes of rickets are known. The latter are due to mutations in genes involved in vitamin D metabolism or action, renal phosphate reabsorption, or synthesis, or degradation of the phosphaturic hormone fibroblast growth factor 23 (FGF23). There is a substantial overlap in the clinical features between the various entities, requiring a thorough workup using biochemical analyses and, if necessary, genetic tests. Part I of this review focuses on the etiology, pathophysiology and clinical findings of rickets followed by the presentation of a diagnostic approach for correct diagnosis. Part II focuses on the management of rickets, including new therapeutic approaches based on recent clinical practice guidelines.

scholarly journals Serum Erythropoietin Concentration And Its Correlation With Stage Of Diabetic Retinopathy

2019 ◽  
Author(s):  
Sofija Davidović ◽  
Babić Nikola ◽  
Jovanović Sandra ◽  
Barišić Sava ◽  
Grković Desanka ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
Serum Concentration ◽  
Proliferative Diabetic Retinopathy ◽  
Elevated Serum ◽  
Serum Levels ◽  
Average Concentration ◽  
Control Group ◽  
Patients With Diabetes ◽  
Advanced Stages

Abstract Erythropoietin (EPO) is one of the systemic angiogenic factors, and its role in ocular angiogenesis and in diabetic retinopathy (DR) is not yet fully understood. The latest research data reveal a possible correlation of higher erythropoietin concentrations in the blood and in the eye with the development of more advanced stages of DR. The main aim of this work was to examine the possible influence of serum concentrations of erythropoietin on the development of diabetic retinopathy in patients with diabetes mellitus type 2.Methods The research involved 90 patients examined at the University Eye Clinic of the Clinical Center of Vojvodina, Novi Sad, Serbia. The first group comprised 60 patients with diabetes mellitus lasting for ten years or more, with diabetic retinopathy. The second, control group consisted of 30 healthy individuals. In the first group of 60 patients with diabetes, 30 of them had non-proliferative diabetic retinopathy (NPDR), and 30 had proliferative diabetic retinopathy (PDR). Laboratory EPO serum levels were determined, and they were correlated to the stage of DR. Concentration of EPO was assessed by ELISA method.Results The highest average concentration of EPO in serum (9.95 mIU/ml) was determined in the group of people with diabetes with PDR. The lowest average concentration of EPO in the serum (6.90 mIU/ml) was found in the control group. The average concentration of EPO in serum in the group of patients with diabetes with NPDR was 7.00 mIU/ml. The EPO concentration in serum was elevated in the group of PDR, and it was directly proportional to the level of the clinical stadium of PDR, being significantly higher in the moderate and severe subgroup of PDR comparing to the control healthy subjects, NPDR and mild PDR (p=0.007).Conclusions Significantly elevated serum concentration of EPO in the advanced stages of DR, and positive correlation between EPO serum concentration and clinical stages of PDR, suggest that erythropoietin represents an important growth factor from blood, which plays a significant role in retinal ischemia and angiogenesis in diabetic retinopathy, especially in the proliferative stage of this disease.

scholarly journals Serum erythropoietin concentration and its correlation with stage of diabetic retinopathy

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Sofija Davidović ◽  
Nikola Babić ◽  
Sandra Jovanović ◽  
Sava Barišić ◽  
Desanka Grković ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Diabetic Retinopathy ◽  
Serum Concentration ◽  
Proliferative Diabetic Retinopathy ◽  
Elevated Serum ◽  
Serum Levels ◽  
Average Concentration ◽  
Control Group ◽  
Patients With Diabetes ◽  
Advanced Stages

Abstract Background Erythropoietin (EPO) is one of the systemic angiogenic factors, and its role in ocular angiogenesis and in diabetic retinopathy (DR) is not yet fully understood. The latest research data reveal a possible correlation of higher erythropoietin concentrations in the blood and in the eye with the development of more advanced stages of DR. The main aim of this work was to examine the possible influence of serum concentrations of erythropoietin on the development of diabetic retinopathy in patients with diabetes mellitus type 2. Methods The research involved 90 patients examined at the University Eye Clinic of the Clinical Center of Vojvodina, Novi Sad, Serbia. The first group comprised 60 patients with diabetes mellitus lasting for 10 years or more, with diabetic retinopathy. The second, control group consisted of 30 healthy individuals. In the first group of 60 patients with diabetes, 30 of them had non-proliferative diabetic retinopathy (NPDR), and 30 had proliferative diabetic retinopathy (PDR). Laboratory EPO serum levels were determined, and they were correlated to the stage of DR. Concentration of EPO was assessed by ELISA method. Results The highest average concentration of EPO in serum (9.95 mIU/ml) was determined in the group of people with diabetes with PDR. The lowest average concentration of EPO in the serum (6.90 mIU/ml) was found in the control group. The average concentration of EPO in serum in the group of patients with diabetes with NPDR was 7.00 mIU/ml. The EPO concentration in serum was elevated in the group of PDR, and it was directly proportional to the level of the clinical stadium of PDR, being significantly higher in the moderate and severe subgroup of PDR comparing to the control healthy subjects, NPDR and mild PDR (p = 0.007). Conclusions Significantly elevated serum concentration of EPO in the advanced stages of DR, and positive correlation between EPO serum concentration and clinical stages of PDR, suggest that erythropoietin represents an important growth factor from blood, which plays a significant role in retinal ischemia and angiogenesis in diabetic retinopathy, especially in the proliferative stage of this disease.

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