Metabolic bone disease in adults receiving long-term parenteral nutrition: longitudinal study with regional densitometry and bone biopsy

Secondary Osteoporosis and Metabolic Bone Diseases

Fragility fracture is a worldwide problem and a main cause of disability and impaired quality of life. It is primarily caused by osteoporosis, characterized by impaired bone quantity and or quality. Proper diagnosis of osteoporosis is essential for prevention of fragility fractures. Osteoporosis can be primary in postmenopausal women because of estrogen deficiency. Secondary forms of osteoporosis are not uncommon in both men and women. Most systemic illnesses and organ dysfunction can lead to osteoporosis. The kidney plays a crucial role in maintaining physiological bone homeostasis by controlling minerals, electrolytes, acid-base, vitamin D and parathyroid function. Chronic kidney disease with its uremic milieu disturbs this balance, leading to renal osteodystrophy. Diabetes mellitus represents the most common secondary cause of osteoporosis. Thyroid and parathyroid disorders can dysregulate the osteoblast/osteoclast functions. Gastrointestinal disorders, malnutrition and malabsorption can result in mineral and vitamin D deficiencies and bone loss. Patients with chronic liver disease have a higher risk of fracture due to hepatic osteodystrophy. Proinflammatory cytokines in infectious, autoimmune, and hematological disorders can stimulate osteoclastogenesis, leading to osteoporosis. Moreover, drug-induced osteoporosis is not uncommon. In this review, we focus on causes, pathogenesis, and management of secondary osteoporosis.

Computed Tomography Osteodensitometry for Assessment of Bone Mineral Density of the Canine Head-Preliminary Results

Simple Summary

Metabolic bone disease can have disastrous consequences on canine health. Unlike in human medicine where awareness of osteoporosis and bone mineral density (BMD) disorders have led to the holistic application of osteodensitometry, application of osteodensitometry in dogs is limited. We aimed to assess the utility of quantitative computed tomography (qCT) bone mineral density (BMD) measurement of the canine calvarium using semiautomated osteodensitometry software and define host factors associated with canine BMD in a skeletally healthy population. Calvarium qCT can be used to rapidly obtain BMD measurement of dogs. Canine BMD was negatively associated with weight, whereas there was no relationship between BMD and age or sex. Many chronic canine diseases can significantly affect bone health via a variety of pathophysiological mechanisms. This efficient qCT method could facilitate rapid BMD screening in dogs undergoing CT evaluation and ultimately encourage further BMD investigation.

Abstract

Despite bone mineral density (BMD) being regularly measured in human patients, BMD studies in clinical cohorts of dogs is lacking. In order to facilitate BMD assessment and in turn better identify dogs suffering from metabolic bone disease, rapid, easy and precise computed tomography (qCT) techniques are required. In this study we aimed to assess the utility of quantitative computed tomography (qCT) bone mineral density (BMD) measurement of the canine calvarium using a semiautomated osteodensitometry software and define host factors associated with canine bone mineral density in a skeletally healthy population. Calvarial qCT at the level of the temporomandibular joints was performed on 323 dogs using a dedicated osteodensitometry calibration phantom during a clinically indicated head computed tomography (CT). Calvarial BMD was analyzed using a dedicated semiautomatic osteodensitometry software for contouring of the calvarial lamellar bone margins and BMD calculation. The mean duration of the calvarial qCT scanning was 64.6 s, and the mean duration of BMD analysis was 34 s, with a mean of two manual adjustments required for the bone margin tracing. The median BMD of all dogs in our study was 659 mg Calcium hydroxyapatite/mL. There was a negative linear correlation between BMD and body weight, but no correlation with age, sex or neutered status. Canine BMD assessment using qCT of the calvarium is a practical and fast technique that can be added to a clinical CT examination with minimal extra time requirements. Canine BMD host-dependent factors exhibit different relationships from that of humans; however, further investigation is warranted.

Metabolic bone diseases in intestinal failure

Metabolic bone diseases are a group of conditions that are common complications in patients with intestinal failure. These may occur as a result of the underlying condition, leading to intestinal failure, particularly inflammatory conditions such as Crohn's disease and their associated treatments including corticosteroids. Malabsorption, as a result of a loss of enterocyte mass or gut function, of many nutrients, including vitamin D, may further compound metabolic bone problems, and there has been historical contamination of parenteral nutrition with aluminium that has prevented normal bone metabolism contributing to osteoporosis. This review looks at the diagnosis and current management of bone health in patients with intestinal failure.

Longitudinal Bone Mineralization Assessment in Children Treated With Long-Term Parenteral Nutrition for Severe Intestinal Failure

BACKGROUND

Metabolic bone disease is common in children receiving home parenteral nutrition (HPN) for intestinal failure (IF). Long-term evolution of bone mass in pediatric IF is poorly documented. The aims of this study were (1) to determine the prevalence of low bone mass (LBM) in children receiving HPN for IF, (2) to evaluate the evolution of total bone mineral content (TBMC) during HPN with dual-energy x-ray absorptiometry (DXA), and (3) to identify related factors.

METHODS

All children referred in our HPN center from 2004 to 2014 were eligible. Inclusion criteria were HPN dependence due to noninflammatory IF, at least 2 TBMC assessments, and HPN duration of at least 2 years at last DXA. TBMC was expressed in z score for ideal weight for height (WFH). LBM was defined by a TBMC WFH z score ≤-2 standard deviations (SD).

RESULTS

A total of 175 DXAs for 31 children were performed, mean of 5.6 ± 2.9 assessments per child. The median time between first and last DXA recorded was 6.2 years (0.7-16.6). At the first DXA, 14 children (45%) had a LBM. TBMC increased by +0.1 ± 0.04 SD per year of HPN (P = .012). The risk of LBM decreased with an odds ratio of 0.9 per year of HPN (95% confidence interval, 0.92-0.99; P = .018). Lean mass z score and calcium parenteral intakes were related to the TBMC improvement.

CONCLUSION

LBM is common in pediatric IF, but bone status could improve during HPN in these children.

The Prevalence of Vitamin D Insufficiency and Deficiency and Their Relationship with Bone Mineral Density and Fracture Risk in Adults Receiving Long-Term Home Parenteral Nutrition

It has been demonstrated that low bone mass and vitamin D deficiency occur in adult patients receiving home parenteral nutrition (HPN). The aim of this study is to determine the prevalence of vitamin D insufficiency and deficiency and its relationship with bone mineral density (BMD) and fracture risk in long-term HPN patients. Methods: A retrospective chart review of all 186 patients in the HPN registry followed by the Northern Alberta Home Parenteral Nutrition Program receiving HPN therapy >6 months with a 25 (OH) D level and BMD reported were studied. Results: The mean age at the initiation of HPN was 53.8 (20–79) years and 23 (37%) were male. The mean HPN duration was 56 (6–323) months and the most common diagnosis was short bowel syndrome. Based on a total of 186 patients, 62 patients were categorized based on serum vitamin D status as follows: 1 (24.2%) sufficient, 31 (50%) insufficient and 16 (25.8%) deficient. Despite an average of 1891 IU/day orally and 181 IU/day intravenously vitamin D, the mean vitamin D level was 25.6 ng/mL (insufficiency) and 26.2 ± 11.9 ng/mL in patients with the highest 10-year fracture risk. Conclusion: Suboptimal vitamin D levels are common among patients on long-term HPN despite nutrient intake that should meet requirements.

Metabolic Bone Disease in Patients Receiving Home Parenteral Nutrition: A Canadian Study and Review

BACKGROUND

Metabolic bone disease (MBD) is a significant complication in patients receiving long-term home parenteral nutrition (HPN). Pamidronate has been poorly studied in this population. We examine the prevalence and risk factors for MBD and examine changes in bone mineral density (BMD) after pamidronate administration.

METHODS

First, a chart review of patients receiving HPN for >1 year was performed, and Pearson correlations were used to assess associations between MBD (defined as t score<-1) and risk factors. Second, the effect of IV pamidronate on BMD was studied prospectively in 11 HPN patients. Results were compared using a t-test.

RESULTS

Charts were reviewed in 25 patients (15 F, 10 M): age, 56.9+/-3.1 years; body mass index (BMI), 21.2+/-0.57 kg/m2; months receiving HPN, 113.2+/-0.09; and days per week receiving HPN, 5.08+/-0.39. MBD was present in 33% of patients for the spine and hip and in 50% for the femoral neck; 24% had previous fractures. There was a significant negative correlation between the duration of HPN and BMD (r=-0.40) for all measurements. From those patients, 11 received IV pamidronate for a mean of 22.2+/-5.4 months. At baseline, their mean HPN treatment duration was 10.6+/-6.3 years. Overall, BMD results showed a trend toward improvement in the mean t score of the spine and hip postpamidronate therapy (pre, -3.1+/-0.75; post, -2.9+/-0.69; p=.07). After excluding 2 patients receiving corticosteroids, the mean t score of the spine showed significant improvement (prepamidronate -3.4+/-0.57 vs post-pamidronate -3.1+/-0.65, p=.036).

CONCLUSIONS

In our HPN population, 76% had MBD and 24% had previous fractures. The results suggest that these patients may benefit from pamidronate. More studies are needed to assess the efficacy of pamidronate.

Growth Hormone Favorably Affects Bone Turnover and Bone Mineral Density in Patients With Short Bowel Syndrome Undergoing Intestinal Rehabilitation

BACKGROUND

Patients with short bowel syndrome (SBS) have a high prevalence of metabolic bone disease due to nutrient malabsorption and potential effects of parenteral nutrition (PN). Human growth hormone (hGH) has been shown in some studies to have anabolic effects on bone, but hGH effects on bone in patients with SBS are unknown.

METHODS

Adults with PN-dependent SBS underwent a 7-day period of baseline studies while receiving usual oral diet and PN and then began receiving modified diets designed to improve nutrient absorption and daily oral calcium/vitamin D supplements (1500 mg elemental calcium and 600 IU vitamin D, respectively). Subjects were randomized to receive in a double-blind manner either subcutaneous (sc) saline placebo as the control or hGH (0.1 mg/kg/d for 3 weeks, then 0.1 mg/kg 3 days a week for 8 subsequent weeks). Open-label hGH was given from week 13 to week 24 in subjects who required PN after completion of the 12-week double-blind phase. Markers of bone turnover (serum osteocalcin and urinary N-telopeptide [NTX]), vitamin D nutriture (serum calcium, 25-hydroxyvitamin D [25-OH D] and parathyroid hormone [PTH] concentrations), and intestinal calcium absorption were measured at baseline and at weeks 4 and 12. Dual x-ray absorptiometry (DXA) of the hip and spine was performed to determine bone mineral density (BMD) at baseline and weeks 12 and 24.

RESULTS

The majority of subjects in each group exhibited evidence of vitamin D deficiency at baseline (25-OH D levels<30 ng/mL; 78% and 79% of control and hGH-treated subjects, respectively). Subjects treated with hGH demonstrated a significant increase from baseline in serum osteocalcin levels at 12 weeks (+62%; p<.05). The levels of NTX were increased over time in the hGH-treated group; however, this did not reach statistical significance. Both NTX and osteocalcin remained unchanged in control subjects. BMD of the spine and total hip was unchanged in subjects treated with placebo or hGH at 24 weeks. However, femoral neck BMD was slightly but significantly decreased in the placebo group at this time point but remained unchanged from baseline in the hGH-treated subjects.

CONCLUSIONS

hGH therapy significantly increased markers of bone turnover during the initial 3 months of therapy and stabilized femoral neck bone mass over a 6-month period in patients with severe SBS undergoing intestinal rehabilitation.

Short Bowel Syndrome and Intestinal Failure in Crohn's Disease

Crohn's disease is a chronic and progressive inflammatory disorder of the gastrointestinal tract. Despite the availability of powerful immunosuppressants, many patients with Crohn's disease still require one or more intestinal resections throughout the course of their disease. Multiple resections and a progressive reduction in bowel length can lead to the development of short bowel syndrome, a form of intestinal failure that compromises fluid, electrolyte, and nutrient absorption. The pathophysiology of short bowel syndrome involves a reduction in intestinal surface area, alteration in the enteric hormonal feedback, dysmotility, and related comorbidities. Most patients will initially require parenteral nutrition as a primary or supplemental source of nutrition, although several patients may eventually wean off nutrition support depending on the residual gut anatomy and adherence to medical and nutritional interventions. Available surgical treatments focus on reducing motility, lengthening the native small bowel, or small bowel transplantation. Care of these complex patients with short bowel syndrome requires a multidisciplinary approach of physicians, dietitians, and nurses to provide optimal intestinal rehabilitation, nutritional support, and improvement in quality of life.

How does long-term parenteral nutrition impact the bone mineral status of children with intestinal failure?

Patients on long-term parenteral nutrition (PN) are at significantly increased risk for the development of metabolic bone disease (MBD); this condition is characterized by incomplete mineralization of osteoid with consequent disturbances ranging from osteopenia to severe bone disease with fractures. The aim of the study was: (1) to evaluate the prevalence of MBD, (2) to identify the PN- or intestinal failure (IF)-related factors and (3) to assess annual changes of bone mineral status. Since September 2005 all patients affected by IF and treated with PN started a BMD evaluation program using dual-energy X-ray absorptiometry (DXA). Twenty-four IF patients were included [15 with short bowel syndrome (SBS), 5 with severe protracted diarrhea and 4 with chronic intestinal pseudostruction]. The bone mineral density (BMD) Z-score was significantly lower in patients than in the control group. In our series SBS patients showed a BMD Z-score significantly higher in comparison with the medical causes of IF. No significant correlations were found between bone mineral status and PN duration and nutrient intake. Nine IF patients were submitted to a second DXA evaluation after 1 year from the baseline. All bone mineral variables were significantly increased at the second DXA evaluation. The high prevalence of MBD in IF patients undergoing long-term treatment with PN requires that these patients undergo careful and periodic monitoring of their bone mineral status; patients with congenital gut dysfunctions, such as epithelium defects and motility anomalies, are at major risk of developing this complication, probably due to the association with extra-intestinal causes of bone loss.

Specific topics and complications of parenteral nutrition

BACKGROUND/AIMS

Total parenteral nutrition (TPN) has proven a tremendous advance in all disciplines in medicine but itself introduces a spectrum of possible complications related to both the parenteral nutritional solution as well as the technique of intravenous delivery. Our aim is to review the specific complications of TPN.

MATERIALS AND METHODS

This article presents a critical literature review of relevant topics in TPN-related complications-metabolic, infections, and nutrition related.

RESULTS

Special emphasis focuses on complications of TPN arising from thrombosis or infectious sequelae related to the central venous catheterization and metabolic complications involving the kidneys, bones, liver, and biliary tract.

CONCLUSIONS

Awareness and surveillance of TPN-related complications can prevent, potentially, some of these complications related to parenteral nutritional support.

Bone mineral density in patients on home parenteral nutrition: a follow-up study

BACKGROUND AND AIMS

The variations of bone mineral density (BMD) during home parenteral nutrition (HPN) and their relationship with general, life style, primary disease and HPN risk factors were investigated by a follow-up study.

DESIGN

Patients who had BMD assessment in a previous cross-sectional survey underwent a 2nd BMD at femoral neck (FN) and lumbar spine (LS). Data about risk factors were collected by a structured questionnaire. BMD Z-score (number of standard deviations from normal values corrected for sex and age) and the annualized percent BMD change were analysed.

RESULTS

Sixty-five adult patients were enrolled (follow-up: 18.1+/-5.5 months). The mean BMD Z-score significantly increased at the LS (P = 0.040) and remained unchanged at FN. In multiple regression analysis, the variations of the LS Z-score during HPN negatively correlated with the female sex (P = 0.021) and the age at starting HPN (P = 0.022). The analysis of the annualized percent BMD change confirmed the results obtained by the analysis of the Z-score. No factor was associated with BMD variation at FN.

CONCLUSIONS

HPN was not associated with a decrease of BMD in most of the patients; LS BMD Z-score variations were related to general risk factors rather than to HPN factors, showing a negative association with age and female sex.

Hepatobiliary, renal and bone complications of intestinal failure

Abnormal liver function tests in patients with intestinal failure (IF) may be due to the underlying disease, IF or the treatments given (including parenteral nutrition (PN)). PN-related liver disease in children usually relates to intrahepatic cholestasis and in adults to steatosis. Steatosis may be consequent upon an excess of carbohydrate, lipid or protein, or upon a deficiency of a specific molecule. Pigment-type gallstones are common in adults and children with IF; these develop from biliary sludge that forms during periods of gallbladder stasis. Ileal disease/resection, parenteral nutrition, surgery, rapid weight loss and drugs all increase the risk of developing gallstones. Gallstone formation may be prevented by reducing gallbladder stasis (oral/enteral feeding or prokinetic agents), altering bile composition, or by means of a prophylactic cholecystectomy. Calcium oxalate renal stones are common in patients with a short bowel and retained functioning colon and are consequent upon increased absorption of dietary oxalate; they are prevented by a low-oxalate diet. An osteopathy may occur with long-term parenteral nutrition.

Osteoporosis in patients on long-term home parenteral nutrition: a longitudinal study

The prevalence of osteoporosis was investigated in 88 patients with intestinal failure (IF). Osteoporosis was found in 67%, dependent of body mass index and age when IF occurred. In 56 patients on HPN, followed prospectively, changes in bone density were dependent on the duration of HPN; older patients had a higher increase.

INTRODUCTION

It has been suggested that low bone mass and negative bone balance may occur in adult patients receiving home parenteral nutrition (HPN). The aim of this study was to assess prospectively the prevalence of osteoporosis in intestinal failure (IF) patients and the changes in bone mineral density in those on long-term HPN and to analyze the factors that may influence the occurrence and evolution of osteoporosis.

MATERIALS AND METHODS

Bone mineral density was measured at the lumbar spine and femoral neck in 88 IF patients.

RESULTS

At the first bone mineral density determination (baseline), the prevalence of osteoporosis was 67% in this population (median age, 52 years). Ten percent of the patients with osteoporosis experienced fragility fractures. Osteoporosis was independent of age and gender but occurred earlier in patients who had received corticosteroids. At baseline, the lumbar Z-score was positively correlated mainly to body mass index and age when IF occurred; these two parameters explained 34% of the Z-score. Repeated measurements were performed in 56 patients during long-term HPN (mean duration, 5.5 +/- 1.2 years). The changes in Z-score at the lumbar spine were dependent on the age when IF occurred and on the duration of HPN, with a synergistic effect between them. The older the patients, the higher the increase in Z-score during HPN.

CONCLUSION

HPN had no deleterious effect on cortical bone and actually improved trabecular bone in patients whose intestinal disease started after the age of 21 years.

Effect of cyclical intravenous clodronate therapy on bone mineral density and markers of bone turnover in patients receiving home parenteral nutrition

BACKGROUND

Patients receiving home parenteral nutrition (HPN) because of intestinal failure are at high risk of developing osteoporosis.

OBJECTIVE

We studied the effect of the bisphosphonate clodronate on bone mineral density (BMD) and markers of bone turnover in HPN patients.

DESIGN

A 12-mo, double-blind, randomized, placebo-controlled trial was conducted to study the effect of 1500 mg clodronate, given intravenously every 3 mo for 1 y, in 20 HPN patients with a bone mass T score of the hip or lumbar spine of less than -1. The main outcome measure was the difference in the mean percentage change in the BMD of the lumbar spine measured by dual-energy X-ray absorptiometry. Secondary outcome measures included changes in the BMD of the hip, forearm, and total body and biochemical markers of bone turnover, ie, serum osteocalcin, urinary pyridinoline, and urinary deoxypyridinoline.

RESULTS

The mean (+/-SEM) BMD of the lumbar spine increased by 0.8 +/- 2.0% in the clodronate group and decreased by 1.6 +/- 2.0% in the placebo group (P = 0.43). At all secondary skeletal sites (ie, hip, total body, and distal forearm), we observed no changes or small increases in the BMD of the clodronate group and decreases in the BMD of the placebo group. In the clodronate group, biochemical markers of bone resorption decreased significantly (P < 0.05).

CONCLUSIONS

Clodronate significantly inhibits bone resorption as assessed by changes in biochemical markers of bone turnover. Although the mean BMD increased in the clodronate group, cyclic clodronate therapy failed to increase spinal BMD significantly at 12 mo.

Prevalence of bone disease in patients on home parenteral nutrition

BACKGROUND & AIMS

The epidemiology of bone disease in home parenteral nutrition (HPN) is unknown. The aim of this paper is to evaluate the prevalence and severity of reduced bone mineral density (BMD) in long-term HPN.

DESIGN

Cross-sectional, multicentre study including patients who within the last 12 months had their BMD assessed by dual-energy-X-ray absorptiometry after at least 6 months of HPN. Data on bone pain and fractures, the primary gastrointestinal diseases, nutritional and rehabilitation status and HPN regimen were reviewed. Both the T-score (no. of SD below mean BMD of young subjects) and the Z-score (no. of SD from normal BMD values corrected for sex and age) were analysed.

RESULTS

A T -score <-1 at any site of assessment was observed in 84% of the 165 patients enrolled (<or= -2.5 in 41%). Bone pain occurred in 35% and bone fracture in 10% of patients. Both T - and Z-scores were significantly lower in symptomatic patients. The frequency of bone disease was higher in post-menopausal women but did not differ among the subgroups of the primary diseases. Stepwise regression analysis showed the lumbar spine Z -score positively associated with the age at starting HPN and the femoral neck Z-score positively associated with the body mass index.

CONCLUSIONS

Bone disease was present in most of the patients on HPN, was of severe degree in one-half of them and symptomatic in one-third. The BMD Z-score appeared predictive of the risk of fracture. The prevalence of bone disease did not differ between the various primary diseases. Age at starting HPN and body mass index appeared to be the major factors associated with BMD Z-scores.

Clinical, social and rehabilitation status of long-term home parenteral nutrition patients: results of a European multicentre survey

BACKGROUND

Home parenteral nutrition (HPN) is a lifesaving treatment in patients with intestinal failure. Dependency of nutritional support becomes permanent for the majority of patients who had received HPN for at least 2 years. The alternative to long term HPN in selected patients is intestinal transplantation.

AIMS

To study some of the clinical, social and rehabilitation aspects of long-term HPN treatment.

METHODS

A survey was performed in nine European HPN centres. The questionnaire covered epidemiologic data, underlying diseases, intestinal anatomy, nutritional support and status, marital status, rehospitalization rate, HPN complications, rehabilitation score, drugs use, coexistent diseases and interest in intestinal transplantation. For some items, data were collected within 12 months prior to the evaluation.

RESULTS

This survey included 228 patients with a median age of 49 years. The median duration of HPN was 7 years (range 2--24 years). Short bowel length less than 100 cm was reported in 65% of patients with a predominance of end-jejunostomy or jejuno-colonic anastomosis. Global subjective nutritional status was normal in 79% of the patients, who were supplied with a mean number of 5.6 bags of parenteral nutrition weekly. Rehospitalizations within the 12 months prior to evaluation accounted for a mean period of 23 days and were due to HPN complications in half of the cases. Catheter-related sepsis was the most frequent HPN-complication. Bone metabolism disorders, which seemed to be more common than liver diseases, were directly related to HPN duration. One-third of the HPN patients was regularly consuming analgesics or opiates. HPN impair complete rehabilitation status but may improve the status of patients who had a very low rehabilitation score before starting HPN. An interest of intestinal transplantation was noted in only 10% of medical teams and in 8% of HPN patients.

CONCLUSIONS

This study is the largest European survey on long-term HPN patients with long standing or permanent intestinal failure. Data enlighten clinical, social and rehabilitation aspects of patients who could face the option of intestinal transplantation in the future.

Complications of long-term home total parenteral nutrition: their identification, prevention and treatment

The purpose of this review is to describe the most common complications of home total parenteral nutrition, their identification, treatment and prevention. Data sources were manuscripts and abstracts published in the English literature since 1968. Studies were selected for summarization in this review on the basis of clinical relevance to the practicing clinician. Home total parenteral nutrition is a relatively safe, life-saving method for nutrient delivery in patients with compromised gastrointestinal function. However, numerous complications, with associated morbidity and mortality, involving the delivery system and the gastrointestinal, renal, and skeletal systems may develop. Catheter-related complications are often preventable and treatable when they occur, although renal and bone abnormalities have elusive etiologies.

Renal function and urinary excretion of electrolytes in patients receiving cyclic parenteral nutrition

BACKGROUND

Long-term parenteral nutrition (LTPN) has been shown to induce renal impairment and bone demineralization. However, the mechanism of both injuries has not been clarified.

METHODS

This prospective study was performed in 16 patients with short bowel syndrome, aged 28 to 63 years, who had received LTPN for 31 +/- 7 months. Urinary excretion of electrolytes were measured before (diurnal, 12 hours) and during (nocturnal, 12 hours) parenteral nutrition. Glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) were measured in the morning after the nutritional bag supply.

RESULTS

Mean GFR was 86 +/- 7 mL/min/1.73 m2 and ERPF was 412 +/- 31 mL/min/1.73 m2. Decreased GFR was present in 9 patients. There was no relation between renal function and age or the duration of LTPN. Urine volume and excretion of urea, creatinine, sodium, magnesium, and phosphate but not potassium increased significantly in nocturnal urine compared with diurnal urine. On the basis on 24-hour calciuria, 7 patients were normocalciuric (NCa) whereas 9 were hypercalciuric (HCa). Both had excessive nocturnal calciuria, but only the HCa group had diurnal hypercalciuria, the calcium supply being identical. Bone mineral density (BMD) was slightly, although not significantly, higher in NCa group, but in all patients BMD correlated significantly with calciuria. Serum parathyroid hormone and vitamin D were not different in the two groups.

CONCLUSIONS

In patients receiving LTPN, renal function is frequently impaired, by a mechanism which remains unclear. In nocturnal cyclic mode of nutrition, urinary volume and electrolyte excretion occurred predominantly during the infusion, but some patients have diurnal hypercalciuria. In these patients a defect in renal calcium reabsorption or more likely the inability of bone to retain the infused calcium may be responsible for bone demineralization.

Bone turnover in short-term and long-term home parenteral nutrition for benign disease

6 mo afterward. Long-HPN was assessed only at baseline. In short-HPN, there was a hyperkinetic turnover at baseline. At follow-up, OC was similar to baseline, whereas cross-links, urinary calcium and magnesium decreased (P < 0.03), and parathyroid hormone increased (P < 0.001). The variation of urinary calcium correlated with that of cross-links (r = 0.73, P < 0.04). In long-HPN, OC was low or low-normal in almost all the patients, and cross-links were normal. Mean OC was lower than that of short-HPN both at baseline (P < 0. 003) and at follow-up (P < 0.002). The results suggest that in the early period of HPN bone metabolism improved from a hyperkinetic turnover to a positive balance. A low bone-formation rate appeared to be a characteristic feature of long-term HPN.

Altered diurnal regulation of blood ionized calcium and serum parathyroid hormone concentrations during parenteral nutrition

BACKGROUND

Little is known about parathyroid gland function in patients receiving total parenteral nutrition (TPN).

OBJECTIVE

Our objective was to determine whether parathyroid gland function is abnormal in TPN recipients.

DESIGN

Six patients with a mean (+/-1 SD) age of 45.5 +/- 8.0 y who had been receiving TPN for 18.7 +/- 2. 8 y underwent bone biopsy, bone mass measurements with dual-energy X-ray absorptiometry, and dynamic tests of parathyroid gland function. Diurnal variations in blood ionized calcium (iCa(2+)) and serum parathyroid hormone (PTH) concentrations were also assessed. Results were compared with those of healthy volunteers.

RESULTS

Bone mass and bone formation were subnormal in all patients. Basal serum PTH concentrations were moderately higher in the TPN recipients than in healthy volunteers, and values obtained every 30 min over 24 h were significantly higher (P < 0.001) in TPN recipients (5.0 +/- 0.9 pmol/L) than in healthy volunteers (2.6 +/- 0.6 pmol/L). The percentage increase in serum PTH during citrate-induced hypocalcemia was lower in the TPN recipients, consistent with secondary hyperparathyroidism. Evening infusions of calcium-containing TPN eliminated the nocturnal rise in serum PTH, increased the amplitude of change for iCa(2+) and PTH over 24 h, increased the orderliness of change for iCa(2+) and PTH as measured by approximate entropy (ApEn), and enhanced the synchrony of change between iCa(2+) and PTH. Treatment for 10 d with calcium-free TPN restored the nocturnal rise in serum PTH and increased ApEn for PTH. ApEn for iCa(2+) remained low, suggesting that a component of nutrient solutions, but not calcium per se, enhances the regularity of PTH release in TPN recipients.

CONCLUSION

Parathyroid gland function is abnormal in long-term TPN recipients, which may contribute to disturbances in bone metabolism.

Home parenteral nutrition. 25 years later

After 25 years, there is enough clinical outcome experience to determine appropriate use of home parenteral nutrition in different disease states and age groups. Information regarding how to avoid complications and how patients and families can find necessary psychosocial support is provided in this article. Currently, small bowel transplantation is not a safer choice, unless there is severe liver disease caused by home parenteral nutrition or lack of central intervenous access.

Long-term growth and development in children after home parental nutrition

Growth and development after the cessation of prolonged parenteral nutrition (PN) has not been fully evaluated. Growth, body composition, and nutritional and developmental status were documented in nine children (five boys, four girls) 2 to 6 years old (mean 4.9 +/- 1.0 years) who had previously received long-term PN (mean 14.6 +/- 11.4 months). PN had been discontinued in all subjects for at least 6 months (mean 3.4 +/- 1.4 years); they were receiving oral feedings only. One subject had a significantly low height-for-age, and another had a low percent ideal body weight; five subjects had low total body fat. Serum vitamin A was low in six subjects. Seventy-two-hour fecal fat analysis was abnormal in two of eight subjects. Abnormal bone mineral density was present in four of nine subjects. Psychomotor development was normal in all nine subjects. Two had functional difficulties in swallowing. One or more abnormalities were present in all nine subjects. These findings suggest that children who require prolonged PN in early life are at risk for abnormalities in growth and nutritional status in later childhood; they require long-term dietary, growth, and nutritional monitoring.

Metabolic bone disease of total parenteral nutrition

Parenteral nutrition-associated metabolic bone disease in children is manifested primarily as osteopenia and, on occasion, fractures. The etiology is likely multifactorial, with calcium and phosphate deficiency playing a major role in the preterm infant and with the role of aluminum toxicity yet to be clearly defined in this population. Lack of normal values of bone histomorphometry in the premature infant as well as lack of normal data for biochemical markers of bone turnover in these patients contribute to the uncertainty. Other factors that may play a role in the pathogenesis include lack of periodic enteral feeding; underlying intestinal disease, including malabsorption and inflammation; the presence of neoplasms; and drug-induced alterations in calcium and bone metabolism. The true incidence and prevalence of parenteral nutrition-associated bone abnormalities in pediatric patients remain unknown.

Body composition changes measured by dual-energy X-ray absorptiometry in patients receiving home parenteral nutrition

BACKGROUND

To monitor changes in body composition in patients receiving home parenteral nutrition (HPN) and to ascertain whether changes were related to the amount of energy supplied by HPN, we studied prospectively patients with gut failure maintained on HPN.

METHODS

Patients were subjected to repeated measurement of body composition by dual-energy X-ray absorptiometry (DXA), the second investigation being performed after a mean period of 20 (range, 11-26) months. Thirty-two patients were included, one patient was excluded, and five patients died during the study period. At inclusion, the patients had received HPN for a mean period of 30 (range, 6-216) months. The indication for HPN was inflammatory bowel disease (n = 16), abdominal cancers (n = 5), and scleroderma and others (n = 11). The fat-free mass (FFM), fat mass (FM), and total body mineral content (TBMC) were measured by DXA.

RESULTS

Mean body mass index decreased from 21.18 to 20.96 kg/m2 (P = 0.36). The mean FFM showed a small, insignificant increase to 37.68 kg (P = 0.71). Mean TBMC was unchanged at 2.28 kg, and mean FM decreased from 19.25 to 18.17 kg (P = 0.055). During the study period the mean daily energy supply by HPN was reduced from kcal 1195 to kcal 959 (P = 0.004). There was a direct positive correlation between the individual changes in HPN energy supply and body weight and FFM (r = 0.437, r = 0.410, P < 0.05).

CONCLUSION

The body composition of HPN patients was stable, with no change in mean FFM, FM, or TBMC. Individual changes in body weight and FFM correlated with change in HPN energy supply.

Bone turnover in patients on home parenteral nutrition: alongitudinal observation by biochemical markers

In order to characterize biochemical markers of bone turnover in home parenteral nutrition(HPN) patients, 8 adult patients on HPN for benign intestinal failure were studied at 0, 6 and 12 months by evaluating serum osteocalcin (bone formation marker), urinary hydroxylysyl pyridinoline, lysyl pyridinoline and beta-galactosyl hydroxylysine (bone resorption markers), serum PTH, Calcitonin, 25 vitD, 1-25vitD, serum and urinary minerals, body weight, rehabilitation degree and HPN characteristics. Three patients entered the study 2-3 months after the beginning of HPN. Their features of bone turnover were homogeneous, characterized by increased resorption associated with normal or increased formation, at baseline, and normalization of resorption associated with an increase or a parallel decrease of formation, at 6 months. At 12 months, the patterns were similar to those observed at 6 months. The patients were not of the same sex and age and had different underlying diseases and types of intestinal failure, HPN composition and serum vitamin D levels. They had weight gain that was already present at baseline and the positive outcomes of the rehabilitation and clinical status in common. Five patients entered the study more than 1 year after the beginning of HPN. They showed heterogeneous features of bone turnover that were stable throughout the study, characterized by increased resorption associated with low or normal formation in two cases, low normal resorption associated with low or normal formation in three. In one patient, who had increased resorption and low formation, the bone turnover appeared to be explained by the nutritional and clinical outcomes, which were negative. These results appeared consistent with those obtained in previous studies by bone histomorphometry, indicating that bone turnover of short-term HPN patients differed from that of long-term patients, and suggesting that the early months of HPN were associated with increased bone resorption.

Bone loss and oral state in patients on home parenteral nutrition

BACKGROUND

The purpose was to analyze changes in the mandible and the forearm bone mineral content and oral state in patients on home parenteral nutrition due to short bowel syndrome in relation to the bone mineral values and oral findings in a normal population.

METHODS

The bone mineral content was measured by dual-photon absorptiometry and the dental and periodontal state were studied in 15 adults patients (12 women, and 3 men, aged 26 to 65 years). All patients were on free oral intake as a supplement to the parenteral nutrition.

RESULTS

Forty-seven percent of the patients (2 males, 2 young and 3 elderly females) showed mandibular osteoporosis (Z-scores < -2.00), and all young females showed Z-scores < 0. Moreover, 34% of the patients showed osteoporosis in the forearm bones (Z-scores < -2.00) and also radiographic signs of osteoporotic fractures of the columna. The dental and the periodontal state in the patients did not differ clearly from that of the normal Danish population of the same age.

CONCLUSIONS

Such patients seem to have a high risk of developing systemic osteoporosis, including the jaws, but apparently do not show a higher risk for deterioration of the dental or periodontal state than age-matching normals from the same population.

Calcitonin and bisphosphonates treatment in bone loss after liver transplantation

Osteopenia is a major complication of orthotopic liver transplantation (OLT). However, no effective therapy for bone disease has been defined. We have studied vertebral bone mineral density (VMD) and fasting serum markers of bone formation [bone gla protein (BGP), procollagen I carboxyterminal peptide (PICP)] and metabolism (serum Ca, P, intact parathyroid hormone (iPTH), 25OHD3 and 1,25(OH)2D3) in 120 patents after OLT. VMD was measured by dual-energy X-ray absorptiometry (DXA) using a Hologic QDR 1000 densitometer on two occasions, 12 months apart. Patients with OLT had a VBD significantly lower compared with age- and sexed-matched Spanish controls (P < 0.05). Prevalence of osteoporosis (Z score below -2 SD) was 35.8%. Serum BGP (8.6 +/- 0.7 ng/ml) and PICP (222.9 +/- 81.9 ng/dl) were higher than those of controls. However, serum calcium, phosphorus, iPTH, 25OHD3, and 1,25(OH)2D3 were within normal range. Patients with osteoporosis were randomly treated with 40 IU/day of calcitonin i.m. (Diatin, Ferrer Int. Laboratories) (n = 17) or 400 mg p.o., 15 days every 3 months, of sodium ethiodronate (Difosfen, Rubio Laboratories) (n = 23). All patients received 500 mg/12 hours of elemental calcium p.o. After 12 months of treatment, a significant increment of vertebral mineral density (VMD) was observed (6.4% and 8.2%, respectively). Serum BGP and PICP values remained elevated without a difference between the two drugs. Our results indicate that antiresorptive drugs may be of benefit in the high turnover osteoporosis of OLT recipients.

Bone mineral content in patients on home parenteral nutrition

Bone mineral content (BMC) was monitored in 15 patients with short bowel syndrome receiving home parenteral nutrition (HPN). Thirteen patients had Crohn's disease and 2 ulcerative colitis (mean age 36 years, range 23-69 years). During the study the patients received HPN for a mean period of 62 months, range 20-106 months. At the time of inclusion the patients had a significantly reduced BMC of lumbar spine and femoral neck compared to normals (Z-scores = -3.35 +/- 3.49, p < 0.05 and Z-score = -2.23 +/- 2.11, p < 0.05). During HPN the Z-score of lumbar spine BMC decreased in 8 patients and increased slightly or was unchanged in 7 patients. The mean Z-score of BMC of lumbar spine declined by 1.46 +/- 2.48 (p < 0.05) and the Z-score of femoral neck BMC declined by 0.831 +/- 1.14 (p < 0.05). This corresponds to a yearly decrease of lumbar spine BMC of 4%. There was no correlation between the decline in BMC during the study and the period of length the patients were on HPN. We conclude that patients on HPN have a low bone mineral density and that the bone loss continues during prolonged HPN.

Body composition: research and clinical advances--1993 A.S.P.E.N. research workshop

The 1993 ASPEN Research Workshop examined research and clinical advances in the study of human body composition. The workshop had two themes: (1) compartments of the body and their measurement, and (2) clinical applications of body composition measurements. There were 12 speakers of varied backgrounds who gave short lectures followed by panel discussions. Speakers explored the validity and potential uses of new body composition methodologies, including dual-energy x-ray absorptiometry, multiple frequency bioimpedance analysis, computerized axial tomography, magnetic resonance imaging, nuclear magnetic resonance spectroscopy, neutron inelastic scattering, and gamma-ray resonance. The application of these methods to chronically and acutely ill hospitalized patients was described. The study of body composition is an emerging distinct research area within the broad study of human biology. This conference provided an overview of important new advances in the study of human body composition.

Total parenteral nutrition and its effects on bone metabolism

Total parenteral nutrition (TPN) may affect bone metabolism in a variety of ways. These may include potential indirect effects such as on gastrointestinal hormone secretion, liver function, especially cytochrome P450 isoenzymes, metabolic biorhythms where established, and the continuous compared with the intermittent supply of nutrients. More substantial evidence exists for the reduction of bone formation, parathyroid hormone secretion, and calcitriol production in TPN patients along with high urinary calcium excretion. This review considers both aluminum loading and vitamin D sensitivity as etiologic factors and suggests that aluminum may have played a primary role in the pathogenesis of these abnormalities in bone and mineral metabolism, but that vitamin D may have potentiated the deleterious actions of aluminum. While the sources of aluminum contamination of TPN solutions have been identified and efforts are under way to reduce its contamination of TPN solutions, the persistence of low bone mass measurement in TPN patients is a problem that has been identified repeatedly, does not have a current explanation, and requires further study.