Bone metabolism and disease--K/DOQI impact on nurses and dietitians

Earlier monitoring and treatment of elevated phosphorus and PTH prior to initiation of dialysis may prevent the development of bone disease. We can no longer be complacent or content with patients having a calcium-phosphorus product of 70 or phosphorus of 6.0. When we strive for the recommended optimal levels and goals and work toward these new goals we will improve our patient outcomes. We must be vigilant and have an increased intensity of focus on bone metabolism as part of the total patient care. The entire team serves to provide ongoing education and encouragement throughout the continuum of care with the CKD client.

Treatment of hypophosphatemia using a protocol based on patient weight and serum phosphorus level in a surgical intensive care unit

BACKGROUND

Hypophosphatemia may cause organ derangements in the surgical intensive care unit. The purpose of this study was to determine the impact of a repletion protocol for hypophosphatemia based on admission weight and phosphorus level.

STUDY DESIGN

All patients who presented to an 18-bed surgical intensive care unit with a serum phosphorus level of 2.2 mg/dL or less or who received phosphorus supplementation despite having normal levels were identified. In the preintervention phase between January and June 2001, 137 patients were retrospectively identified who met these criteria. A protocol was then designed giving a single intravenous dose of phosphorus based on weight and serum phosphorus. Repletion was given with sodium or potassium phosphorus based on presupplementation levels. After protocol implementation 141 patients met these criteria between September 2001 and February 2002, and treatment and postrepletion levels were followed prospectively.

RESULTS

A total of 47 patients were repleted before the intervention with adequate followup and 22 (47%) attained a normal level. Supplementation success was 53% in moderate hypophosphatemia (2.2 mg/dL or less) and 27% in severe hypophosphatemia (less than 1.5 mg/dL). After protocol implementation, 111 patients were repleted with 84 (76%) correcting to a normal level (p = 0.002 compared with retrospective patients). Success was 78% in moderate hypophosphatemia and 62% in severe hypophosphatemia. Inappropriate supplementation of normal phosphorus levels decreased from 51 to 16 patients after protocol implementation.

CONCLUSIONS

A protocol based on weight and serum levels successfully treated both moderate and severe hypophosphatemia in the majority of critically ill patients. Protocol implementation also decreased unnecessary supplementation of normal phosphorus levels.

No mutation in the SLC2A2 ( GLUT2) gene in a Turkish infant with Fanconi-Bickel syndrome

Fanconi-Bickel syndrome (FBS), or glycogen storage disease type XI, is a rare, well-defined clinical entity. Recently, this disease was elucidated to link mutations in the SLC2A2 gene in many ethnic groups, indicating that FBS is a single gene disease. We report here an 8-month-old Turkish girl who developed characteristic findings of FBS. However, no mutation was detected in the protein-coding region of the SLC2A2 gene. Therefore, we propose that further molecular analysis is needed to determine whether other genes are involved in FBS.

[Galstena therapy of some hepatobiliary diseases]

Galstena was given to 10 patients with chronic cholecystitis, 15 patients with chronic hepatitis and 15 patients with fatty degeneration of the liver for 30 days in a dose 10 drops 3 times a day 30 min before meal. The effect of the drug was assessed in relation to biliary inflammation and motility, inflammation and metabolism in a hepatic cell. It was found that galstena improves motor function of the biliary tract and exocrine function of the liver, reduces activity of mesenchymo-inflammatory syndrome and fatty degeneration of the liver.

Parathyroid hormone changes during phosphorus load in patients with chronic renal insufficiency with low serum parathyroid hormone or adynamic bone disease

Adynamic bone disease (ABD) is frequently associated with low serum parathyroid hormone (PTH) concentrations. Many clinical and therapeutic conditions have been associated with ABD, and recently, a low phosphorus intake accompanied by low serum concentration of phosphorus and PTH has been described.

AIM

To evaluate the parathyroid gland response of chronic renal insufficiency patients (CRI) with low serum PTH or ABD to a phosphorus load.

METHODS

We examined the effects of 0.5 and 1.0 g/d of phosphorus load over a period of 60 days in 18 patients with mild CRI with a bone biopsy showing ABD (n = 7) or with low serum PTH (serum intact PTH < or = 40 ng/l) and serum phosphorus < 4.5 mg/dl (n = 11).

RESULTS

Serum intact PTH increased significantly only after 1 g of phosphorus (58.5 to 83 ng/l) with a median percent increase of 72%. PTH secretion increased more in patients with lower basal PTH levels (81%). Serum phosphorus did not change significantly and urinary phosphorus increased from 487 to 1,062 mg/dl (p < 0.05). Significant decreases in serum ionized calcium (from 1.26 to 1.19 mmol/l) and calcitriol (from 34.5 to 24.9 pg/ml) were observed. Changes in PTH were inversely correlated with changes in serum ionized calcium (r = -0.54, p < 0.05) and the final PTH concentrations were positively correlated with changes in serum phosphorus (r= 0.52, p < 0.05).

CONCLUSIONS

The parathyroid glands of chronic renal insufficiency patients with "relative hypoparathyroidism" or ABD responded to a phosphorus load with an increase in serum PTH levels. The decrease in serum ionized calcium and calcitriol as well as minimal changes in serum phosphorus appeared to be involved in this response.

Cardiovascular disease: C-reactive protein and the inflammatory disease paradigm: HMG-CoA reductase inhibitors, alpha-tocopherol, red yeast rice, and olive oil polyphenols. A review of the literature

The current understanding of the origin of atherosclerosis is that of an inflammatory process that involves the acute phase response -an innate biological response to a disturbance in homeostasis -infection, inflammation, tissue injury, neoplasm, or immune disturbance. The activation of the acute phase response, signaled by interleukin-6, produces proteins (fibrinogen, C-reactive protein (CRP), serum amyloid A) that lead to inflammatory reactions. The tissues themselves contain elevated levels of acute phase proteins and cytokines resulting in a localized inflammatory effect. Localized inflammatory responses in the intimal layer of the arterial wall have been shown to be responsible for many of the aspects of intimal thickening and plaque disruption, leading to acute cardiovascular events. The predictive value of plasma C-reactive protein as a risk factor for cardiovascular events has led some researchers to support the use of CRP as a main cardiovascular risk assessment tool, along with total cholesterol:HDL ratios and homocysteine levels. The ability of HMG-CoA reductase inhibitors to lower C-reactive protein levels has recently brought into question the mechanisms of action of the statin drugs. Because these medications lower incidences of acute cardiovascular events as well as decreasing morbidity and mortality well before the effects of lowered LDL cholesterol can be expected to occur, questions have been asked about whether they may work independently of LDL-lowering mechanisms. Red yeast rice contains a naturally-occurring statin (lovastatin) as well as other cholesterol-lowering compounds, some with antioxidant effects. Alpha-tocopherol also significantly lowers CRP levels in diabetics and nondiabetics, and minimizes other aspects of the acute phase response and inflammatory damage involved in atherosclerosis. This may account for alpha-tocopherol's positive effect on cardiovascular morbidity and mortality. Finally, polyphenolic compounds present in virgin olive oil also have anti-inflammatory and antioxidative effects in cardiovascular disease. The phenolic compounds in virgin olive oil may explain some of the protective effects found in epidemiological studies.

Herbs and atherosclerosis

It is now widely accepted that atherosclerosis is a complex multicellular process involving oxidation of cholesterol and the intracellular accumulation of oxidized cholesterol. This accumulation causes a cascade of inflammatory processes, resulting in an unstable atherosclerotic plaque that ultimately bursts, causing myocardial infarction. Botanical dietary supplements (herbs) can ameliorate this process and prevent cardiovascular disease at many steps in the process. Many herbs have antioxidant activity and can reduce low-density lipoprotein oxidation. Some phytosterols found in botanicals can inhibit cholesterol absorption. After a brief review of herbs being promoted for achieving and maintaining healthy cholesterol levels, the evidence and future prospects for Chinese red yeast rice, the main component of dietary supplements with HMG-CoA reductase inhibiting activity, are discussed in detail. Initial phase II clinical trials are highly encouraging. This herb is likely to be able to directly impact the process of atherosclerosis, but large-scale clinical trials are needed to assess the public health potential of this herbal supplement.

Management of hypophosphatemia induced by high-flux hemodiafiltration for the treatment of vancomycin toxicity: intravenous phosphorus therapy versus use of a phosphorus-enriched dialysate

Intensive high-flux hemodiafiltration is often used in the management of vancomycin toxicity. We describe two patients who developed hypophosphatemia as a consequence of this form of therapy. The first patient was treated with an intravenous phosphorus infusion. For the second patient, hypophosphatemia was corrected, during hemodiafiltration, with the use of a phosphorus-enriched dialysate. The latter dialysate was prepared by adding sodium phosphate salts to the "base concentrate" of a dual-concentrate, bicarbonate-based dialysate delivery system. This simple method was more efficient than intravenous therapy in ameliorating the hypophosphatemia secondary to aggressive hemodiafiltration treatment.

Enamel defects in primary and permanent teeth of children born prematurely

The objective of this study was to determine the prevalence of enamel defects in both primary and permanent dentitions of the same preterm children, and to elucidate the role of early dietary mineral and vitamin D intake in the etiology of the enamel defects. The status of the primary and permanent teeth was evaluated in 32 preterm children and in 64 control children. The prevalence of enamel defects in children born preterm was clearly higher as compared with controls in both the primary (78% vs 20%, P<0.001) and permanent (83% vs 36%, P<0.001) dentitions. Neither the mineral supplementation used nor a vitamin D dose of 1000 IU/day, as compared with a lower dose of 500 IU/day, reduced the prevalence of enamel defects in the primary or permanent dentitions. Further studies are needed to clarify whether achieving near optimum intra-uterine mineral retention would lower the prevalence of subsequent enamel defects in infants born prematurely.

Cholesterol-lowering effects of a proprietary Chinese red-yeast-rice dietary supplement

BACKGROUND

We examined the cholesterol-lowering effects of a proprietary Chinese red-yeast-rice supplement in an American population consuming a diet similar to the American Heart Association Step I diet using a double-blind, placebo-controlled, prospectively randomized 12-wk controlled trial at a university research center.

OBJECTIVE

We evaluated the lipid-lowering effects of this red-yeast-rice dietary supplement in US adults separate from effects of diet alone.

DESIGN

Eighty-three healthy subjects (46 men and 37 women aged 34-78 y) with hyperlipidemia [total cholesterol, 5.28-8.74 mmol/L (204-338 mg/dL); LDL cholesterol, 3.31-7.16 mmol/L (128-277 mg/dL); triacylglycerol, 0.62-2.78 mmol/L (55-246 mg/dL); and HDL cholesterol 0.78-2.46 mmol/L (30-95 mg/dL)] who were not being treated with lipid-lowering drugs participated. Subjects were treated with red yeast rice (2.4 g/d) or placebo and instructed to consume a diet providing 30% of energy from fat, <10% from saturated fat, and <300 mg cholesterol daily. Main outcome measures were total cholesterol, total triacylglycerol, and HDL and LDL cholesterol measured at weeks 8, 9, 11, and 12.

RESULTS

Total cholesterol concentrations decreased significantly between baseline and 8 wk in the red-yeast-rice-treated group compared with the placebo-treated group [(x+/-SD) 6.57+/-0.93 mmol/L (254+/-36 mg/dL) to 5.38+/-0.80 mmol/L (208+/-31 mg/dL); P < 0.001]. LDL cholesterol and total triacylglycerol were also reduced with the supplement. HDL cholesterol did not change significantly.

CONCLUSIONS

Red yeast rice significantly reduces total cholesterol, LDL cholesterol, and total triacylglycerol concentrations compared with placebo and provides a new, novel, food-based approach to lowering cholesterol in the general population.

Disturbance of consciousness associated with hypophosphatemia in a chronically alcoholic patient

A 69-year-old man with chronic alcoholism was admitted to our hospital due to disturbance of consciousness and oliguria. Emergency laboratory examination revealed metabolic acidosis, hypoglycemia, hyponatremia, mild liver dysfunction, acute renal failure and rhabdomyolysis. After administration of fluids and nutrients and continuous hemodiafiltration, he recovered from all signs and symptoms except for disturbance of consciousness after 7 days. Since severe hypophosphatemia persisted, we administered adequate phosphates, and then his level of consciousness normalized. We discuss the relationships among alcohol abuse, hypophosphatemia and disturbance of consciousness, and recommend that hypophosphatemia be considered a potential cause of disturbance of consciousness in alcoholic patients.

Hemodialysis-induced hypophosphatemia in a normophosphatemic patient dialyzed for ethylene glycol poisoning: treatment with phosphorus-enriched hemodialysis

Hypophosphatemia developed in a normophosphatemic patient after 9 h of hemodialysis therapy (using a phosphate-free dialysate) administered for the treatment of ethylene glycol poisoning. The hypophosphatemia was promptly improved with additional hemodialysis treatment using a phosphorus-enriched dialysate.

Use of a phosphorus-enriched hemodialysate to prevent hypophosphatemia in a patient with renal failure-related pericarditis

We describe a patient who suffered from renal failure-associated pericarditis and underwent daily 3.5-hour hemodialysis treatments for 17 days. The initially elevated serum phosphorus level gradually fell to below normal on days 11 and 12 as a result of the intensive dialytic therapy. Phosphorus was added to the "base concentrate" of a dual-concentrate, bicarbonate-based dialysate delivery system on days 13 to 17. Because of this phosphorus-enrichment, we were able to maintain the patient's serum phosphorus levels within normal limits in spite of continued daily dialysis treatments.

Inorganic phosphorus reduces hypercalciuria during total parenteral nutrition by enhancing renal tubular calcium absorption

BACKGROUND

Increasing the inorganic phosphorus content of total parenteral nutrition (TPN) formulas has been shown to decrease TPN-induced hypercalciuria in experimental animals and humans. The mechanism of this effect, however, has been uncertain.

METHODS

By using a randomized cross-over design, seven patients on cyclic TPN were given otherwise identical formulas providing either 15 or 45 mmol/d of inorganic phosphorus. Urinary calcium excretion, serum ultrafilterable calcium, filtered calcium load, fractional calcium excretion, urinary cyclic adenosine 5'-monophosphate (cAMP), and serum levels of ionized calcium, parathyroid hormone (PTH), and vitamin D metabolites were determined at the end of each study period.

RESULTS

Urinary calcium excretion was significantly lower when the patients received the higher inorganic phosphorus formula. Increasing the inorganic phosphorus in the TPN formula did not change ultrafilterable calcium or filtered calcium load, but significantly reduced fractional calcium excretion. No differences in serum levels of ionized calcium, PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, or urinary cAMP were observed between treatments.

CONCLUSIONS

These results demonstrate that increasing the inorganic phosphorus content of the TPN formula decreases urinary calcium excretion by increasing renal tubular calcium resorption. This effect is not due to alterations in the PTH-1,25-dihydroxyvitamin D axis, but likely reflects a direct action of inorganic phosphorus on the renal tubules.

Orthodontic treatment of a patient with hypophosphatemic vitamin D-resistant rickets

Hypophosphatemic vitamin D-resistant rickets, when developed later in life, is less severe and may not be characterized by rickets or other osseous deformities. A Japanese girl, age nine years and one month, was first seen in the Dental Hospital of Osaka University, complaining of the crowding of the maxillary teeth. At one year of age, the patient was admitted to Osaka University Hospital for her leg deformities. Although the patient has been administered 4 micrograms 1 alpha/-hydroxyvitamin D3 and 1.0 g phosphorous daily, the serum phosphate has been low and never reached normal level. This case was a Class II division 2 malocclusion with severe anterior crowding and retarded mandibular growth. We treated her with a functional appliance (elastic open activator), followed by the extraction of four premolars and the use of an edgewise appliance. No unfavorable root resorption or bone defect occurred. Good occlusion was achieved and the facial features were pleasing.

A 3-month-old baby with multiple fractures

This case is presented to illustrate the radiographic and clinical findings of a condition of interest to orthopedic surgeons. The initial findings are noted on this page. The clinical and radiographic diagnoses are presented on the following pages.

Analysis of dental health education activity carried out by dentistry students

During their career, students of dentistry acquire techniques which they will employ later on their patients. Since the health of these patients and society itself cannot be left exclusively to the professional activity of these future dentist, an experimental extra-class experience was carried out with pupils from primary and secondary schools. The students gave the pupils presentations on Nutrition, Calcium and Phosphorus and Caries. The aim of this study was to evaluate: a) the influence of society on the teaching process, and training during the first university year, and b) epidemiologic aspects. Our results indicated that 32.2% of the primary and 15.6 % of the secondary school pupils were unfamiliar with the disciplines presented by the students. According to the evaluations 78.1% of the primary and 94.0% of the secondary school pupils achieved or exceeded the minimum requirements considered necessary for correct nutritional and oral health habits. Evaluations of the students demonstrated that the students who had participated in the activity did not have knowledge superior to that of non-participating students. Therefore this experience can be considered an exercise in utilizing human resources for primary prevention rather than an innovative methodology which improves the teaching-learning process. It also seems recommendable in view of the low cost of the exercise.

Congenital rickets--a patient report

We present a premature newborn with congenital rickets, born to a mother with untreated chronic renal insufficiency. X-ray films showed blurred metaphyseal ends and decreased bone density in the femurs and ribs. With treatment including calcium, phosphate, and vitamin D, her rickets healed and she grew normally.

Body growth in primary de Toni-Debré-Fanconi syndrome

Body growth in nine children with primary de Toni-Debré-Fanconi syndrome was followed from birth to adolescence or adult life. At the time of diagnosis, corresponding to the start of treatment, the median age was 2.3 (range 0.4-13.9) years and height standard deviation score (SDS) was always decreased (median -3.5, range -6.8 to -2.1). Despite continuous electrolyte and bicarbonate supplementation only four patients showed a slight improvement in growth. At the time of the last observation at the age of 17.2 (4.5-20.1) years median height was -4.7 (-5.9 to -1.8) SDS. The median difference between height at last observation and target height was -4.5 SDS. Final height (n = 5) ranged between -1.8 and -5.5 (median -4.3) SDS. The pubertal growth spurt was absent in two children. Metabolic acidosis was identified as a significant growth-retarding factor. Mean serial blood bicarbonate levels and height SDS at the last observation were correlated (r = -0.87, P < 0.01). No correlation was observed between last height SDS and the degree of hypokalemia, hypophosphatemia, or hypercalciuria. In conclusion, patients with primary de Toni-Debré-Fanconi-syndrome present severe growth failure at the time of diagnosis which persists into adult life. Supportive therapy is frequently unable to prevent further loss of relative height.

Acute recumbency and marginal phosphorus deficiency in dairy cattle

Because of a mixing error at a local feed mill, a diet marginally deficient in phosphorus, compared with recommendation from the National Research Council, was fed to a high-producing dairy herd for 5 months. Two mature cows in early lactation became recumbent. Serum phosphorus concentration in 1 cow was low (1.8 mg/dl), but was not measured in the other cow. Ten other high-producing, first-lactation cows in the herd developed severe lameness. Results of analysis of rib bone samples from the recumbent cows were consistent with changes associated with demineralization. Bone ash, calcium, phosphorus, and magnesium concentrations were lower than published ranges for healthy cattle. Serum calcium, phosphorus, and magnesium concentrations in 8 unaffected cows were normal. For 6 unaffected cows, mean serum hydroxyproline concentration was higher during the period that the phosphorus-deficient diet was fed than when an adequate diet was fed. Moderate (15%) restrictions in dietary phosphorus intake, compared with National Research Council recommendations, can possibly result in health problems in high-producing dairy cattle.

Antacid-induced osteomalacia

The case of a 49-year-old woman suffering from generalized skeletal pain and multiple fractures accompanied by severe hypophosphataemia and low urinary phosphorus excretion is reported. She had been taking large amounts of antacids containing aluminum hydroxide for many years. A diagnosis of antacid-induced osteomalacia was made. It was confirmed by biological work-up, radiographs and bone biopsy. A dramatic biological, osteodensitometric, and clinical improvement was achieved by withdrawal of antacids and phosphorus administration. The literature concerning this unusual condition has been reviewed.

Use of a phosphorus-enriched dialysate in a hypercatabolic renal failure patient receiving intensive hemodialysis therapy

An elderly man with end-stage renal disease required intensive hemodialysis therapy because of sepsis-induced hypercatabolism. We were able to prevent the occurrence of hypophosphatemia by using a phosphorus-enriched dialysate during hemodialysis treatments.

High incidence of hypophosphatemia in surgical intensive care patients: efficacy of phosphorus therapy on myocardial function

OBJECTIVE

To determine the incidence of hypophosphatemia in a surgical intensive care unit and to determine whether or not a phosphorus challenge causes a change in cardiac performance in hypophosphatemic patients.

DESIGN

Prospective clinical study and case reports.

SETTING

Surgical intensive care unit in an university hospital.

PATIENTS

A total of 208 consecutive patients admitted to the surgical ICU were evaluated over a 6 months period.

INTERVENTIONS

All classical risk factors for hypophosphatemia were recorded. A group of 8 moderate or severe hypophosphatemic patients were evaluated for hemodynamic data before and after a phosphorus load. Glucose phosphate was given over 30 min by the intravenous route. Dosage regimen was 0.4 mmol/kg weight for moderate hypophosphatemia and 0.8 mmol/kg weight for severe hypophosphatemia.

RESULTS

Risk factors were present in 134 patients and 60 patients were hypophosphatemic (44.8%). Only 3 risk factors were discriminant for hypophosphatemia: sepsis, diuretics and total parenteral nutrition. The mortality was higher in the hypophosphatemic group than in the normophosphatemic group (30% versus 15.2%; p < 0.05). Cardiac performance improved after phosphatemia normalization in all patients (cardiac index: 3.82 +/- 1.87 versus 4.52 +/- 1.83 1/min.m2; p < 0.01).

CONCLUSION

This study underlines the high incidence (28.8%) of hypophosphatemia in surgical intensive care patients and its association with a high mortality rate (30%). A short course of phosphotherapy improves cardiac index (+18%).

Osteomalacia with hypophosphatemia and hypercalciuria: a possible new variant of osteomalacia

A 12-year-old girl had a severe genu valgum deformity and osteomalacia with hypophosphatemia, hypercalciuria, and modestly elevated levels of 1,25-dihydroxyvitamin D3 and intact parathyroid hormone. This patient seems to have a different type of hypophosphatemic osteomalacia from that previously described.

Hypothesis: myopia of prematurity is caused by postnatal bone mineral deficiency

Myopia is a frequent finding in preterm children. The close association between myopia and retinopathy of prematurity (ROP) suggested a causal relationship, but myopia of prematurity without ROP has yet to be explained. An alternative explanation is presented: myopia is caused by postnatal ellipsoid deformation of the spheric eyeball, i.e. excessive elongation of the optical, as a result of a dolichocephalic deformation of the skull with a short frontal axis. This deformation of the skull is the direct result of bone mineral deficiency frequently observed in very low birth weight infants with increasing postnatal age. This hypothesis is supported by the results of a historical comparison of very low birth weight infants without and with supplementation with calcium and phosphorus that was given in order to prevent postnatal bone mineral deficiency. In the unsupplemented group 4 of 23 children (61%) needed spectacles but only 6 out of 55 (11%) children who were supplemented as babies (questionnaire). Refraction measurements showed myopia stronger than -1 o.d. in group 1 in 5 of 14 infants, whereas in group 2 only 2 out of 22 infants were myopic (P < 0.05).

Calcium, phosphorus and magnesium intakes correlate with bone mineral content in postmenopausal women

Qualitative and quantitative differences in the dietary habits of postmenopausal women were studied to assess their influence on bone health and osteoporosis. A total of 194 postmenopausal women were studied with forearm DEXA densitometry. 70 were osteoporotic and 124 served as controls. Women had been menopausal for 5-7 years, and had never been treated with hormone replacement or drug therapy. A 3-day dietary recall was completed on Sunday, Monday and Tuesday after the examination: the results were processed by computer and daily calcium, phosphorus and magnesium intakes were related to bone mineral content (BMC). Data were compared with Student's t-test and significance was assessed at p < 0.05. Regression analysis was performed to correlate BMC and intake levels. The dietary intake of calcium, phosphorus and magnesium was significantly reduced in osteoporotic women and correlated with BMC. Calcium and magnesium intakes were lower than the recommended daily allowance even in normal women. The results suggest that nutritional factors are relevant to bone health in postmenopausal women, and dietary supplementation may be indicated for the prophylaxis of osteoporosis. Adequate nutritional recommendations and supplements should be given before the menopause, and dietary evaluation should be mandatory in treating postmenopausal osteoporosis.

Type I glycogenosis with renal tubular dysfunction (presentation of two cases)

Two patients with hepatic glycogenosis associated with Fanconi syndrome are presented. Both patients were treated with a neutral phosphorus solution, an oral alkaline solution, cholecalciferol and uncooked cornstarch. The proximal renal tubular functions were corrected in the patient who used cornstarch properly, which may indicate a causal relationship between Fanconi syndrome and glycogenosis.

Effect of parenteral calcium and phosphorus therapy on mineral retention and bone mineral content in very low birth weight infants

HYPOTHESIS

If calcium and phosphorus are administered to very low birth weight infants in amounts larger than those currently used in standard parenteral nutrition solutions, apparent retention of calcium and phosphorus (intake minus urinary excretion) will increase and bone mineralization will improve.

DESIGN

Randomized, controlled, double-blind trial.

SETTING

Neonatal intensive care unit.

PATIENTS

Twenty-four very low birth weight infants (< 1.2 kg) expected to receive parenteral nutrition exclusively for approximately 3 weeks beginning 3 days after birth.

INTERVENTIONS

Infants received parenteral nutrition solutions, either the standard mixture containing 1.25 mmol calcium and 1.5 mmol phosphorus per deciliter (group STAND: n = 12, birth weight 921 +/- 171 gm, gestational age 27 +/- 2 weeks (mean +/- SD)) or 1.7 mmol calcium and 2.0 mmol phosphorus per deciliter (group HIGH: n = 12, 857 +/- 180 gm, 27 +/- 2 weeks).

MAIN OUTCOME MEASURES

Intake, urinary excretion, and apparent retention of calcium, phosphorus, and magnesium every 3 days during parenteral nutrition therapy. Serum indexes of mineral status twice during therapy. Bone mineral content of the distal segment of the left radius at 1, 4, 8, and 26 weeks.

RESULTS

Apparent calcium retention (1.2 +/- 0.2 vs 1.6 +/- 0.2 mmol.kg-1.d-1) and phosphorus retention (1.4 +/- 0.2 vs 1.8 +/- 0.4 mmol.kg-1.d-1) differed significantly (p < 0.01) between groups STAND and HIGH, respectively; neither changed with the duration of parenteral nutrition therapy. Serum calcium, magnesium, parathyroid hormone, 25-hydroxyvitamin D, and osteocalcin concentrations were similar in both groups. Serum phosphorus concentration was significantly higher in group HIGH than in group STAND (p = 0.025). The absolute bone mineral content and the rate of increase in bone mineral content between 1 and 4, 1 and 8, and 1 and 26 weeks were significantly greater in group HIGH than in group STAND.

CONCLUSIONS

Increased parenteral intakes of calcium and phosphorus resulted in greater retention of these minerals during parenteral nutrition therapy and in greater bone mineral content after therapy.

Effects of calcitriol and phosphorus therapy on the growth of patients with X-linked hypophosphatemia

Patients with X-linked hypophosphatemic rickets exhibit clinically evident derangements that include bowed legs and short stature. Although contemporary treatment may result in healing of the rachitic/osteomalacic disorder and straightening of the lower extremities, therapy often does not stimulate growth. Whether such persistent short stature is related to the variable physical manifestations of the disease, the baseline biochemistries, and/or the biochemical response to treatment remains unknown. Therefore, we studied 12 children with X-linked hypophosphatemia to determine if their growth response to calcitriol/phosphorus therapy was dependent upon anthropomorphic characteristics and/or the pre- and posttreatment biochemistries. We observed that growth responsive and resistant youths exhibited similar serum calcium, phosphorus, and creatinine levels at presentation and during therapy. In addition, sexual development was indistinguishable in both groups and growth kinetics appeared independent of physical deformity. In contrast, growth resistant youths presented at less than the 5th percentile whereas growth responsive children were at the 15th percentile or greater. Thus, our data indicate that growth response to calcitriol/phosphate therapy is not a consequence of the biochemical response to therapy or physical deformities. Rather, the criterion that best predicts the growth response is the height percentile at the inception of therapy.

Severe hypophosphatemia in postoperative patients

Severe hypophosphatemia may develop in postoperative patients for several reasons including alcohol withdrawal, diabetic ketoacidosis, nutritional recovery (refeeding) syndrome, and severe respiratory alkalosis. Severe hypophosphatemia may result in central nervous system abnormalities, muscle weakness, and renal, hepatic, cardiac, and respiratory dysfunction. Hypophosphatemia may be prevented by close monitoring of phosphorus concentrations in serum, especially in patients predisposed to developing this problem. Proper techniques for the maintenance and repletion of phosphate for both enteral and parenteral use are described.

Effect of cyclical therapy with phosphorus and etidronate on axial bone mineral density in postmenopausal osteoporotic women

Forty seven women with postmenopausal osteoporosis and at least one but no more than four vertebral compression fractures received sequential and cyclical therapy with phosphorus and etidronate (p/etid). During the same 2-year period of observation, three other groups of patients received either sodium fluoride (n = 12), estrogen replacement therapy (n = 12), or vitamin D and calcium (Ca++) alone (n = 15). Axial bone mineral density (BMD) was measured by means of dual-photon absorptiometry. Lateral thoracic and lumbar spine radiographs were taken to assess fractures. Bone mineral density increased from baseline during p/etid therapy: Mean 15.7 +/- 1.6% (SD) (P less than 0.001). During the same time, the patients in the sodium fluoride group showed a comparable increase in their BMD from baseline: mean 15.7 +/- 1.1% (P less than 0.001). During the first year of therapy, patients in the estrogen replacement group had an increase in their BMD from baseline: mean: 4.6% +/- 1.1% (P less than 0.05). No change in BMD was seen in the control group that received vitamin D and Ca++ alone. No patient who received p/etid, sodium fluoride, or estrogen replacement therapy had any new vertebral compression fractures or height loss, whereas in the control group that received vitamin D and Ca++ alone 6 out of 15 had height loss and at least one new vertebral fracture (P less than 0.01). p/etid therapy increases BMD in women with postmenopausal osteoporosis comparable to sodium fluoride but without side effects or toxicity and stabilizes vertebral compression fractures.

Effects of dietary ammonium chloride and variations in calcium to phosphorus ratio on silica urolithiasis in sheep

Ammonium chloride was added to diets varying in Ca content to evaluate its potential in preventing silica urolith formation in sheep. A 2 x 2 factorial experiment involved wether lambs with ad libitum access to a diet of 50% grass hay and 50% ground oats plus supplement. The basal diet contained on a DM basis 3.3% SiO2, .31% Ca, .22% P, 11.6% CP, and 26% ADF. Treatments (38 to 39 lambs/treatment) consisted of a control (C), limestone to increase dietary calcium to .6% (L), 1% ammonium chloride (A), and L + A (LA). After a 118-d experimental period, siliceous kidney deposits were found only in C and L, with silica making up 93% to 95% of the urolithic ash. Urolith incidences were 13% (C) and 18% (L), respectively. The lack of urolith development in lambs fed A and LA (ammonium chloride effect, P less than .01) and a trend toward a lower urolith incidence in C vs L (P less than .02) support the hypothesis that acid-forming effects of the diet and a reduction in the dietary Ca to P ratio reduce silica urolith formation.

Potential role of acute hypophosphatemia during hypokalemic periodic paralysis attack

A paralysis attack was induced by glucose load in a patient with hypokalemic periodic paralysis. A profound drop in serum phosphorus was observed (from 3.0 to 0.8 mg/dl) in parallel to the serum potassium decrease. The potential role of phosphorus metabolism in the pathophysiology of muscle weakness in this disease is discussed.

[Oncogenic hypophosphatemic osteomalacia]

In the courses of six years a severe hypophosphataemic osteomalacia, painful motor impairment and multiple rib fractures developed in a 51-year-old man. The symptoms gradually improved within one year under treatment with 3 micrograms daily of 1,25-dihydroxycholecalciferol, 3 g phosphorus and 3 g calcium, and biochemical parameters and the bone scintigram became normal. Ultimately, computed tomography, scintigraphy and digital subtraction angiography revealed a highly vascularized tumour in the condylar aspect of the right femur, and it was chiselled out. Histologically it was a mesenchymal phosphaturic tumour of haemangiopericytoma type of questionable benignity. After the operation the patient was symptom-free for some weeks without any drug treatment, but the latter was then resumed because of renewed bone pain. By now, two years later, he is essentially without pain and has full mobility. However, repeat scintigraphy and angiography revealed renewed tumour growth in the right femoral condyle.

Absent intestinal response to calciferols in hereditary resistance to 1,25-dihydroxyvitamin D: documentation and effective therapy with high dose intravenous calcium infusions

We describe a patient with an absent intestinal response to 1,25-dihydroxyvitamin D [1,25-(OH)2D] and the beneficial effects of treatment with high dose iv calcium infusion. The patient presented with severe rickets despite therapy with extraordinarily high doses of 1 alpha-hydroxyvitamin D3 or 1,25-(OH)2D3. Unidirectional intestinal fractional calcium absorption when he was not treated with any calciferol was 14% (normal, 20-70%), as measured with stable calcium isotopes; no increase in calcium absorption occurred when serum 1,25-(OH)2D levels were more than 50-fold elevated. Cultured skin fibroblasts contained no detectable 25-hydroxyvitamin D3-24-hydroxylase activity in response to 1,25-(OH)2D3 (10(-9)-10(-6) mol/L). High dose iv calcium infusions and oral phosphorus supplementation for 135 days improved or normalized biochemical parameters and resulted in radiographic healing of the rachitic lesions. We conclude that 1) this patient had no response to 1,25-(OH)2D3 in vivo and in vitro; 2) long term parenteral calcium infusions were effective therapy in managing the patient's severe resistance to 1,25-(OH)2D; and 3) stable calcium isotopes are useful for measuring low levels of fractional calcium absorption.

Evaluation of mineral metabolism and bone turnover in osteoporotic females treated with phosphorus and salmon calcitonin

Twenty-five patients with radiological and clinical evidence of osteoporosis were studied. Nineteen patients received oral phosphorus at a dose of 1,000 mg/die for 10 days followed by salmon calcitonin (100 U MRC/die) for 20 days. Six patients received only oral calcium at a dose of 1,000 mg/die). In the first group, a significant increase in serum osteocalcin and parathyroid hormone, after administration of phosphorus and persisting after treatment with salmon calcitonin, was found. No variation in the controls was observed. In a later study, a significant increase in serum 1,25 dihydroxyvitamin D (1,25(OH)2D3), after receiving phosphorus and persisting after salmon calcitonin, was demonstrated. In accordance with the authors' results, phosphorus could be considered a useful activator of bone formation and this stimulus by parathyroid hormone was mediated. Finally, the positive effects of phosphorus on circulating 1,25(OH)2D3 must be considered for a good treatment protocol of osteoporosis.

Phosphorus deficiency syndrome in very low birth weight infants

Inadequate dietary phosphorus intake is a contributing factor to the occurrence of metabolic bone disease in very low birth weight infants. This article reviews the clinical presentation and the pathophysiology of the phosphorus deficiency syndrome in premature infants. Recommendations for therapy and prevention of phosphorus deficiency are presented.