A Systematic Review of Clinical Practice Guidelines for Identification and Management of Frailty

OBJECTIVE

This study aims to appraise and summarize consistent recommendations from clinical practice guidelines (CPGs) for identification and management of frailty to maintain and improve functional independence of elderly population.

METHODS

A systematic search of Ovid MEDLINE, Embase, PubMed, PsycINFO, and CINAHL electronic databases using database-specific search terms in two broad areas "guidelines" and "frailty", and a manual search of websites with the key phrase "frailty guideline" was performed. The inclusion criteria included CPGs focusing on identifying and managing frailty in population >65 years old, published in English since January 2010. Three reviewers independently assessed guideline quality using the AGREE II instrument. Data extraction was performed, followed by compilation and comparison of all recommendations to identify the key consistent recommendations.

RESULTS

Six CPGs met the inclusion criteria; however, only three CPGs had high methodological quality in accordance with AGREE II appraisal. The average AGREE II scores of all six CPGs were: 84.5%, 68%, 46.5%, 81.5%, 56.3%, and 60.2% for domains 1-6 (scope and purpose, stakeholder involvement, rigour of development, clarity of presentation, applicability, and editorial independence) respectively. A total of 54 recommendations were identified, with 12 key recommendations suggested frequently by the CPGs.

CONCLUSION

The AGREE II instrument identified strengths and weaknesses of the CPGs, but failed to assess clinical implications and feasibility of the guidelines. Further research is needed to improve clinical relevance of CPGs in the identification and management of frailty. The feasibility in implementing these guidelines with regards to cost-effectiveness of frailty screening warrants further investigation.

International Exercise Recommendations in Older Adults (ICFSR): Expert Consensus Guidelines

The human ageing process is universal, ubiquitous and inevitable. Every physiological function is being continuously diminished. There is a range between two distinct phenotypes of ageing, shaped by patterns of living - experiences and behaviours, and in particular by the presence or absence of physical activity (PA) and structured exercise (i.e., a sedentary lifestyle). Ageing and a sedentary lifestyle are associated with declines in muscle function and cardiorespiratory fitness, resulting in an impaired capacity to perform daily activities and maintain independent functioning. However, in the presence of adequate exercise/PA these changes in muscular and aerobic capacity with age are substantially attenuated. Additionally, both structured exercise and overall PA play important roles as preventive strategies for many chronic diseases, including cardiovascular disease, stroke, diabetes, osteoporosis, and obesity; improvement of mobility, mental health, and quality of life; and reduction in mortality, among other benefits. Notably, exercise intervention programmes improve the hallmarks of frailty (low body mass, strength, mobility, PA level, energy) and cognition, thus optimising functional capacity during ageing. In these pathological conditions exercise is used as a therapeutic agent and follows the precepts of identifying the cause of a disease and then using an agent in an evidence-based dose to eliminate or moderate the disease. Prescription of PA/structured exercise should therefore be based on the intended outcome (e.g., primary prevention, improvement in fitness or functional status or disease treatment), and individualised, adjusted and controlled like any other medical treatment. In addition, in line with other therapeutic agents, exercise shows a dose-response effect and can be individualised using different modalities, volumes and/or intensities as appropriate to the health state or medical condition. Importantly, exercise therapy is often directed at several physiological systems simultaneously, rather than targeted to a single outcome as is generally the case with pharmacological approaches to disease management. There are diseases for which exercise is an alternative to pharmacological treatment (such as depression), thus contributing to the goal of deprescribing of potentially inappropriate medications (PIMS). There are other conditions where no effective drug therapy is currently available (such as sarcopenia or dementia), where it may serve a primary role in prevention and treatment. Therefore, this consensus statement provides an evidence-based rationale for using exercise and PA for health promotion and disease prevention and treatment in older adults. Exercise prescription is discussed in terms of the specific modalities and doses that have been studied in randomised controlled trials for their effectiveness in attenuating physiological changes of ageing, disease prevention, and/or improvement of older adults with chronic disease and disability. Recommendations are proposed to bridge gaps in the current literature and to optimise the use of exercise/PA both as a preventative medicine and as a therapeutic agent.

Letter to the Editor: Healthy for Life: An Innovative and Collaborative Approach to COVID 19 Lockdown in New Zealand

Recently Boreskie and colleagues published an editorial in the Journal of Frailty and Aging on Preventing Frailty Progression During the COVID-19 Pandemic (1). In it they proposed the SAVE programme (Socialization, Adequate nutrition, Vitamin D, Exercise) to prevent frailty. They concluded that creative thinking and concerted efforts would be needed to disseminate health recommendations to maintain the health of pre-frail and frail older adults in unprecedented times, such as those posed by the COVID-19 pandemic.

Letter to the Editor: Implementing Home-Based Exercise Technology in a Nursing Home: Does MCI Status Matter?

The scientific literature highlights the necessity of implementing appropriate exercise programs in nursing homes to overcome the barriers to physical activity, and avoid prolonged periods of sedentary (e.g. sitting) and autonomy decline among residents. Growing evidence indicates that exergaming approaches for physical activity promotion, such as interactive video games, lead to increased enjoyment and motivation in addition to positive cognitive and physical outcomes, while being cost effective (1). The Jintronix Rehabilitation System®(JRS), a new home-based exercise technology, that has a unique ability to adapt to individuals’ limitations (i.e. range of motion, speed, intensity, etc.), and increasing difficulty of games as well as automated reminders and feedback can provide users with an increased sense of control and self-efficacy, which is something that other systems lack (2). Previous studies have demonstrated that the JRS is feasible, acceptable and safe in various population such as community-living older adults who sustained a minor injury (3) or pre-disabled older adults without dementia or cognitive impairment (4). Given its potential, we explored the feasibility, acceptability and efficacy of the JRS on physical performance in nursing home residents both with and without MCI.

Sex-specific muscle and metabolic biomarkers associated with gait speed and cognitive transitions in older adults: a 9-year follow-up

Physical frailty and cognitive frailty share biological mechanisms, but sex-specific biomarkers associated with transitions in gait speed and cognition during ageing are poorly understood.Gait speed, cognition (3MSE), body composition (DXA) and serological biomarkers were assessed annually over 9 years in 216 males (72.7 + 8.07 years) and 384 females (71.1 + 8.44 years). In females, maintaining normal gait speed was associated with lower percent body fat (IRR 0.793, p = 0.001, 95%CI 0.691-0.910) and lower lactate dehydrogenase (LDH) (IRR 0.623, p = 0.00, 95%CI 0.514-0.752), and in males, the association was with higher cholesterol (IRR 1.394, p = 0.001, 95%CI 1.154-1.684). Abnormal to normal gait speed transitions were associated with higher insulin in females (IRR 1.325, p = 0.022, 95%CI 1.041-1.685) and lower creatinine in males (IRR 0.520, p = 0.01, 95%CI 0.310-0.870). Normal to slow gait speed transitions in males were associated with IGF-1 (IRR 1.74, p = 0.022, 95%CI 1.08-2.79) and leptin in females (IRR 1.39, p = 0.043, 95%CI 1.01-1.91.) Maintaining normal cognition was associated with lower LDH in females (IRR 0.276, p = 0.013, 95%CI 0.099-0.765) and higher appendicular skeletal muscle mass in males (IRR 1.52, p = 0.02, 95%CI 1.076-2.135). Improved cognition was associated with higher leptin (IRR 7.5, p = 0.03, 95%CI 1.282-44.34) and lower triglyceride (IRR 0.299, p = 0.017, 95%CI 0.110-0.809) in males. Education was protective against cognitive decline in females (IRR 0.84, p = 0.037, 0.732-0.982). Sex-specific biomarkers of muscle (LDH, Creatinine, IGF-1, APSM) and metabolism (%fat, insulin,cholesterol, leptin, tryglycerides) were associated with gait speed and cognitive transitions. These data suggest that modifiable biomarkers of muscle and metabolism could be targeted for interventions.

Designing Drug Trials for Frailty: ICFSR Task Force 2018

To reduce disability and dependence in older adults, frailty may represent an appropriate target for intervention. While preventing frailty through lifestyle interventions may be the optimal public health approach for many population groups, pharmacological approaches will likely be needed for individuals who meet frailty criteria or who have comorbid conditions that contribute to and complicate the frailty syndrome, and for those who are not compliant with lifestyle interventions. Barriers to successful development of drug treatments for frailty include variability in how the frailty syndrome is defined, lack of agreement on the best diagnostic tools and outcome measures, and the paucity of sensitive, reliable, and validated biomarkers. The International Conference on Frailty and Sarcopenia Research Task Force met in Miami, Florida, on February 28, 2018, to consider the status of treatments under development for frailty and discuss potential strategies for advancing the field. They concluded that at the present time, there may be a more productive regulatory pathway for adjuvant treatments or trials targeting specific functional outcomes such as gait speed. They also expressed optimism that several studies currently underway may provide the insight needed to advance drug development for frailty.

Relationship of Incident Falls with Balance Deficits and Body Composition in Male and Female Community-Dwelling Elders

OBJECTIVE

Sarcopenia and obesity are reported risk factors for falls, although the data are not consistent and most studies do not make sex comparisons. We investigated whether falls were associated with balance, gait, and body composition, and whether these relationships are sex-specific.

DESIGN

Secondary analysis of 4-year follow-up data from of the New Mexico Aging Process Study.

SETTING

Albuquerque, New Mexico.

PARTICIPANTS

307 participants (M, n=122, 75.8 yr. SD5.5; F, n=183, 74.6yr SD6.1).

MEASUREMENTS

Gait and balance were assessed annually using the Tinetti test. Lean body mass (LBM), appendicular skeletal muscle mass (ASM), fat free mass (FFM), total fat mass (FM) were assessed annually by DXA. Falls were assessed using bimonthly falls calendars. Hazard ratios (HR) for 2-point worsening in gait and balance score and falls were calculated by Cox proportional hazard for men and women.

RESULTS

Baseline balance deficits, and not body composition, represented the strongest predictor of falls. For the total balance score, the variables with significant sex interactions were ASM (Male-HR 1.02 95%CI 0.60-1.73; Female-HR 1.92 95%CI 1.05-3.52, p=0.03) and FFM (Male-HR 1.04 95%CI 0.64-1.70; Female-HR 1.91 95%CI 1.12-3.24, p=0.04), after adjustment for age, sarcopenia and physical activity. The body composition relationship with balance deficits was U-shaped with the strongest predictors being low LBM in males and high FM in females.

CONCLUSIONS

Specific body composition components and balance deficits are risk factors for falls following sex-specific patterns. Sex differences need to be explored and considered in interventions for worsening balance and falls prevention.

Physical Frailty: ICFSR International Clinical Practice Guidelines for Identification and Management

OBJECTIVE

The task force of the International Conference of Frailty and Sarcopenia Research (ICFSR) developed these clinical practice guidelines to overview the current evidence-base and to provide recommendations for the identification and management of frailty in older adults.

METHODS

These recommendations were formed using the GRADE approach, which ranked the strength and certainty (quality) of the supporting evidence behind each recommendation. Where the evidence-base was limited or of low quality, Consensus Based Recommendations (CBRs) were formulated. The recommendations focus on the clinical and practical aspects of care for older people with frailty, and promote person-centred care. Recommendations for Screening and Assessment: The task force recommends that health practitioners case identify/screen all older adults for frailty using a validated instrument suitable for the specific setting or context (strong recommendation). Ideally, the screening instrument should exclude disability as part of the screening process. For individuals screened as positive for frailty, a more comprehensive clinical assessment should be performed to identify signs and underlying mechanisms of frailty (strong recommendation). Recommendations for Management: A comprehensive care plan for frailty should address polypharmacy (whether rational or nonrational), the management of sarcopenia, the treatable causes of weight loss, and the causes of exhaustion (depression, anaemia, hypotension, hypothyroidism, and B12 deficiency) (strong recommendation). All persons with frailty should receive social support as needed to address unmet needs and encourage adherence to a comprehensive care plan (strong recommendation). First-line therapy for the management of frailty should include a multi-component physical activity programme with a resistance-based training component (strong recommendation). Protein/caloric supplementation is recommended when weight loss or undernutrition are present (conditional recommendation). No recommendation was given for systematic additional therapies such as cognitive therapy, problem-solving therapy, vitamin D supplementation, and hormone-based treatment. Pharmacological treatment as presently available is not recommended therapy for the treatment of frailty.

Establishing an Operational Definition of Sarcopenia in Australia and New Zealand: Delphi Method Based Consensus Statement

BACKGROUND

Globally there are several operational definitions for sarcopenia, complicating clinical and research applications.

OBJECTIVE

The objective of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Task Force on Diagnostic Criteria for Sarcopenia was to reach consensus on the operational definition of sarcopenia for regional use by clinicians and researchers.

METHOD

A four-Phase modified Delphi process was undertaken in which 24 individuals with expertise or a recognised interest in sarcopenia from different fields across Australia and New Zealand were invited to be Task Force members. An initial face-to-face meeting was held in Adelaide, South Australia, in November 2017, followed by two subsequent online Phases conducted by electronic surveys. A final Phase was used to approve the final statements. Responses were analysed using a pre-specified strategy. The level of agreement required for consensus was 80%.

RESULTS

In Phase 2, 94.1% of Task Force respondents voted in favour of adopting an existing operational definition of sarcopenia. In Phase 3, 94.4% of respondents voted in favour of adopting the European Working Group on Sarcopenia in Older People (EWGSOP) definition as the operational definition for sarcopenia in Australia and New Zealand.

CONCLUSION

With consensus achieved, the ANZSSFR will adopt, promote and validate the EWGSOP operational definition of sarcopenia for use by clinicians and researchers in Australia and New Zealand.

International Clinical Practice Guidelines for Sarcopenia (ICFSR): Screening, Diagnosis and Management

OBJECTIVES

Sarcopenia, defined as an age-associated loss of skeletal muscle function and muscle mass, occurs in approximately 6 - 22 % of older adults. This paper presents evidence-based clinical practice guidelines for screening, diagnosis and management of sarcopenia from the task force of the International Conference on Sarcopenia and Frailty Research (ICSFR).

METHODS

To develop the guidelines, we drew upon the best available evidence from two systematic reviews paired with consensus statements by international working groups on sarcopenia. Eight topics were selected for the recommendations: (i) defining sarcopenia; (ii) screening and diagnosis; (iii) physical activity prescription; (iv) protein supplementation; (v) vitamin D supplementation; (vi) anabolic hormone prescription; (vii) medications under development; and (viii) research. The ICSFR task force evaluated the evidence behind each topic including the quality of evidence, the benefit-harm balance of treatment, patient preferences/values, and cost-effectiveness. Recommendations were graded as either strong or conditional (weak) as per the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Consensus was achieved via one face-to-face workshop and a modified Delphi process.

RECOMMENDATIONS

We make a conditional recommendation for the use of an internationally accepted measurement tool for the diagnosis of sarcopenia including the EWGSOP and FNIH definitions, and advocate for rapid screening using gait speed or the SARC-F. To treat sarcopenia, we strongly recommend the prescription of resistance-based physical activity, and conditionally recommend protein supplementation/a protein-rich diet. No recommendation is given for Vitamin D supplementation or for anabolic hormone prescription. There is a lack of robust evidence to assess the strength of other treatment options.

Systematic review of the impact of osteoarthritis on health outcomes for comorbid disease in older people

OBJECTIVE

A systematic review was undertaken examining the impact of comorbid osteoarthritis on health outcomes for people aged 50 years or older with cardiovascular disease, diabetes or obesity.

DESIGN

The protocol is registered in PROSPERO (CRD42015023417). Relevant electronic databases and grey literature were systematically searched for studies published in English between January 2005 and December 2016. Two reviewers independently screened studies for selection using predetermined inclusion and exclusion criteria, and independently completed methodological quality review. Data was extracted at study level by one reviewer and independently checked by a second reviewer, using a standardized form. The results across studies were qualitatively synthesized with outcomes described and summarized.

RESULTS

Of 1456 articles, we identified 15 relevant studies, with nine good to high quality studies describing significant negative impact of osteoarthritis on outcomes for cardiovascular diseases. There were too few studies focussing on diabetes and obesity to make conclusions in regard to these diseases.

CONCLUSIONS

This review provides evidence that osteoarthritis should not be overlooked when impacts of chronic disease on health outcomes and related health service use are considered. There is a clear need for more studies that consider the impacts of osteoarthritis on comorbid disease, especially those that consider the impact of osteoarthritis beyond the morbidity impacts. The management of comorbid osteoarthritis should be addressed for those with cardiovascular disease, and treatment choices considered given this association.

Reversible States of Physical and/or Cognitive Dysfunction: A 9-Year Longitudinal Study

OBJECTIVES

To determine 1) age-adjusted transition probabilities to worsening physical/cognitive function states, reversal to normal cognition/physical function, or maintenance of normal state; 2) whether these transitions are modulated by sex, BMI, education, hypertension (HTN), health status, or APOE4; 3) whether worsening gait speed preceded cognition change, or vice versa.

DESIGN

Analysis of 9-year prospective cohort data from the New Mexico Aging Process Study.

SETTING

Healthy independent-living adults.

PARTICIPANTS

60+ years of age (n= 598).

MEASUREMENTS

Gait speed, cognitive function (3MSE score), APOE4, HTN, BMI, education, health status.

RESULTS

Over 9 years, 2129 one-year transitions were observed. 32.6% stayed in the same state, while gait speed and cognitive function (3MSE scores) improved for 38% and 43% of participants per year, respectively. Transitions to improved function decreased with age (P< 0.001), APOE4 status (P=0.02), BMI (P=0.009), and health status (P=0.009). Transitions to worse function were significantly increased for the same factors (all P<0.05). Times to lower gait speed and cognitive function did not precede each other (P=0.91).

CONCLUSIONS

Transitions in gait speed and cognition were mutable with substantial likelihood of transition to improvement in physical and cognitive function even in oldest-old, which may have clinical implications for treatment interventions.

Gender Specific Associations between Frailty and Body Composition

BACKGROUND

Frailty is a widespread geriatric syndrome, but its relationship with body composition is largely unknown.

OBJECTIVES

Assess the relationship between body composition and frailty in older persons.

DESIGN, PARTICIPANTS AND SETTING

Cross-sectional data analyses in 120 community-dwelling older persons (50 men, 70 women, mean age 78.5 ± 6 yr).

MEASUREMENTS

Frailty was measured according to Fried's criteria and calculated as a score, and also a binary variable. Anthropometric measures were obtained (height, weight), and body composition (total lean body mass, appendicular skeletal muscle mass (ASM), total fat mass, and percentage fat), assessed by dual energy x-ray absorptiometry. Multiple regression and logistic regression analyses stratified by gender were conducted.

RESULTS

Frailty, as a binary measure, was more prevalent in women than men (67.1% vs 46% p=0.04). Prevalence of low muscle mass (ASM/ht2) was higher in men than in women (40.0% vs 32.9%, p=0.04). Using gender-specific percentage fat cut-scores (27% men, 38% women, respectively) obesity was more prevalent in women than men (58.6% vs 34%, respectively, p=0.01). Multiple regression models showed age as an independent associated factor of frailty in men (β 0.310, p=0.009) and women (β .581 p<0.001). ASM/ht2 was a significant associated factor in men (β -0.517, p<0.001) and trended towards significance in women (β -0.188, p=0.06). Percentage fat was a significant associated factor in women only (β 0.234, p=0.02). Logistic regression with frailty as a binary dependent variable yielded similar results.

CONCLUSION

In this sample of older adults, the significant associated factor of frailty in men was ASM/ht2, whereas it was percentage fat in women. These associations were independent of age. With increasing longevity and the high prevalence of sarcopenia and obesity in older populations, these findings have public health implications. Larger sample and specifically designed studies are needed in order to confirm and extend these findings.

Social Engagement of Frail Elders

BACKGROUND

Social isolation is a significant problem for frail older adults and the determinants of social engagement are poorly understood.

OBJECTIVES

This study explored the social engagement of frail elders to identify personal attributes associated with social engagement.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional sample of seventy-three people receiving home-based care in one town on the South Island of New Zealand (mean age 82 (7.2) yrs, n=51 Females, 21 Males).

MEASUREMENTS

Face-to-face semi-structured interviews and questionnaires. Functional independence was measured using Nottingham Extended Activities of Daily Living (EADL), self-efficacy by General Self Efficacy Scale, and 2 open-ended questions were piloted on social activities and helping others.

RESULTS

Regression models identified two statistically associated components of social engagement: social activities and civic involvement. Contributions to families and community organizations and exercise were important social activities. Personal attributes included perceived functional independence and self-efficacy.

CONCLUSIONS

In frail older adults, a measurement of social engagement should address activities older adults identify as important, including exercise. Independence, self -efficacy, and social engagement may interact in reinforcing cycles of empowerment and could play a role in developing interventions to retain and maintain function in frail older adults.

Sexually dimorphic patterns of nutritional intake and eating behaviors in community-dwelling older adults with normal and slow gait speed

OBJECTIVES

Assess sex-specific nutritional intake and dietary habits of independently living older adults with normal and slow gait speeds.

DESIGN

New Mexico Aging Process Study, cross-sectional, secondary data analysis.

SETTING

Albuquerque, New Mexico USA.

PARTICIPANTS

Three-hundred fifteen adults 60 years and older (194 women and 121 men).

MEASUREMENTS

Gait speed test, 3-day diet records, Mini-Mental State Examination, and body mass index.

RESULTS

Slow gait speed was associated with lower total calories (-154 kcal/day) and zinc (1 mg/day) (.05 < p < .1). Slower men consumed less protein (-4.1 g/day), calcium (-140 mg), fiber (-2.8 g/day) and iron (-2.5 mg/day) (p≤.05). Slower women consumed less, protein (-5.5 g/day), carbohydrate (-19.1 g/day), fiber (-2.7 gm/day), vitamin C (-18.4 mg/day) and higher fat intake (p=0.03). Slower women snacked less, had trouble chewing/biting, and lived alone (p= .04). Slower men were less likely to snack.

CONCLUSIONS

We found sex-specific nutritional differences associated with gait speed. Those presenting with slow gait speed may need encouragement to increase meat and whole grain breads/cereal. Those with trouble eating should be advised on adapting diet to maintain adequate nutrition and encouraged on regular snacking to achieve higher nutrient intake. Prospective and randomized controlled studies are needed to confirm these findings and provide further evidence for putting these suggestions into practice.

Long-term maintenance of weight loss after lifestyle intervention in frail, obese older adults

OBJECTIVES

To determine if long-term weight loss with associated improvement in physical and metabolic health can be maintained after lifestyle intervention in frail, obese older adults.

DESIGN

Thirty-month follow-up pilot study of a 1-year lifestyle intervention trial.

SETTING

Community.

PARTICIPANTS

Sixteen frail, obese (body mass index=36±2 kg/m2) older (71±1 yr.) adults.

MEASUREMENTS

Body weight and composition, physical function, markers of the metabolic syndrome, glucose and insulin response to an oral glucose tolerance test, bone mineral density (BMD), liver and renal function tests, and food diaries.

RESULTS

At 30-month follow-up, weight (101.5±3.8 vs. 94.5±3.9 kg) and BMI (36.0 ±1.7 vs. 33.5±1.7 kg/m2) remained significantly below baseline (all p<0.05). No significant change in fat-free mass (56.7±2.1 vs. 56.9±2.2 kg) or appendicular lean mass (24.1±1.0 vs. 24.1±1.1kg, all p>0.05) occurred between 12 months (end of trial) and 30 months. Improvements in the physical performance test (PPT 27±0.7 vs. 30.2±0.6), insulin sensitivity (4.1±0.8 vs. 3.0±0.6), and insulin area under the curve (12484±2042 vs. 9270±1139 min.mg/dl) remained at 30 months compared to baseline (all p<0.05). Waist circumference (116±3 vs. 109±3 cm) and systolic blood pressure (134±6 vs. 123±5 mm HG) remained decreased at 30 months compared to baseline (all p<0.05). Whole body and lumbar spine BMD did not change; however, total hip BMD progressively decreased at 30 months compared to baseline (0.985±.026 vs. 0.941±.024 g/cm2; p<0.05). There were no adverse effects on liver or renal function. Food frequency questionnaire data showed lower overall caloric intake (-619±157 kcal/day) at 30 months compared to baseline (p<0.05).

CONCLUSION

These findings suggest that long-term maintenance of clinically important weight loss is possible in frail, obese older adults. Weight maintenance appears to be achieved through continued caloric restriction. Larger, long-term studies are needed to follow up on these findings and investigate mechanisms and behaviors underlying maintenance of weight loss and physical function.

Advantages of dietary, exercise-related, and therapeutic interventions to prevent and treat sarcopenia in adult patients: an update

Sarcopenia is the loss of skeletal muscle mass and function with aging. Although the term sarcopenia was first coined in 1989, its etiology is still poorly understood. Moreover, a consensus for defining sarcopenia continues to elude us. Sarcopenic changes in the muscle include losses in muscle fiber quantity and quality, alpha-motor neurons, protein synthesis rates, and anabolic and sex hormone production. Other factors include basal metabolic rate, increased protein dietary requirements, and chronic inflammation secondary to age-related changes in cytokines and oxidative stress. These changes lead to decreased overall physical functioning, increased frailty, falls risk, and ultimately the loss of independent living. Because the intertwining relationships of these factors are complex, effective treatment options are still under investigation. The published data on sarcopenia are vast, and this review is not intended to be exhaustive. The aim of this review is to provide an update on the current knowledge of the definition, etiology, consequences, and current clinical trials that may help address this pressing public health problem for our aging populations.

Osteoporosis and gait and balance disturbances in older sarcopenic obese New Zealanders

Bone, muscle, and fat may affect gait and balance in older adults. Osteoporosis was prevalent in low muscle mass participants and related to gait and balance deficits. Low muscle combined with high fat mass had more functional deficits and poorer bone health, which has implications for falls risk and fractures.

INTRODUCTION

Decreasing bone density and muscle mass and increasing fat mass may act synergistically to affect gait and balance in older adults.

METHODS

One hundred eighty-three older adults (age 72.7 +/- 6 years, range 56-93; body mass index 28.2 +/- 4.9, range 16.6-46.0) were recruited from a New Zealand falls prevention intervention trial. Total and appendicular skeletal muscle mass (ASM), percent fat, and bone mineralization were assessed by dual energy X-ray absorptiometry and used to characterize normal lean (NL, n = 51), sarcopenic (SS, n = 18), sarcopenic obese (SO, n = 29), and obese (OO, n = 85) phenotypes. Functional performance was assessed using timed up and go, chair stand, single leg stand, and step test. Regression models were adjusted for age, sex, medications, and physical activity.

RESULTS

Femoral neck osteoporosis was present in 22% SS, 17% SO, 12% NL, and 7% OO. Femoral neck osteoporosis with low ASM predicted poor chair stand performance (beta -3.3, standard error 1.6, p = 0.04). SO scored lowest on the chair stand (p = 0.03) and step test (p = 0.03). Higher ASM predicted faster timed up and go performance (p = 0.001).

CONCLUSIONS

Osteoporosis was prevalent in low ASM groups (SS and SO) and related to gait and balance deficits, particularly in the SO. This has implications for falls risk, fractures, and interventions.

Mitochondrial function in physically active elders with sarcopenia

Physical activity is reported to protect against sarcopenia and preserve mitochondrial function. Healthy normal lean (NL: n=15) and sarcopenic (SS: n=9) participants were recruited based on body composition (DXA, Lunar DPX), age, and physical activity. Gastrocnemius mitochondrial function was assessed by (31)P MRS using steady-state exercise in a 4T Bruker Biospin. Total work (429.3+/-160.2J vs. 851.0+/-211.7J, p<0.001) and muscle volume (p=0.006) were lower in SS, although these variables were not correlated (NL r=-0.31, p=0.33, SS r=(0.03, p=0.93). In the SS resting ATP/ADP was lower (p=0.03) and ATP hydrolysis higher (p=0.02) at rest. Free energy ATP hydrolysis was greater at the end of exercise (p=0.02) and [ADP] relative to total work output was higher in SS (ANCOVA, p=0.005). [PCr] recovery kinetics were not different between the groups. Adjusting these parameters for differences in total work output and muscle volume did not explain these findings. These data suggest that aerobic metabolism in physically active older adults with sarcopenia is mildly impaired at rest and during modest levels of exercise where acidosis was avoided. Muscle energetics is coordinated at multiple cellular levels and further studies are needed to determine the loci/locus of energy instability in sarcopenia.

Behaviors underlying the use of nonvitamin nonmineral dietary supplements in a healthy elderly cohort

OBJECTIVE

The purpose of the study was to examine factors underlying the decision to use nonvitamin, nonmineral (NVNM) dietary supplements in a healthy elderly cohort.

DESIGN

Questionnaires were administered to probe for perceived health status, health insurance coverage, income level, monthly expenditure for supplements, duration of supplement use, information source, disclosure of supplement taking to physician, reasons for NVNM supplements use and perceived benefits, use of supplements to replace or complement a medication, and usual purchasing place.

SETTING/PARTICIPANTS

Between 1999- 2001, 418 elderly males (34.7%) and females (65.3%) ages 60-96 years were surveyed.

RESULTS

Nonvitamin nonmineral supplement "consumers" and "non-consumers" were not significantly different for sex, age, ethnicity, perceived health status, income level, and health insurance access. The average consumer took three NVNM supplements and spent significantly more money on supplements than non-consumers (p < 0.001). Over 44% of consumer's responses indicated that they had been using NVNM supplements for over 2 years. Literature/media were predominately the source of information with mail order being the most frequent method of purchase. Over 39% of consumer's responses showed that supplement use was revealed to a physician. Arthritis, memory improvement, and general health and well-being were the main reasons to use NVNM supplements. Less joint pain/improved mobility was the main perceived improvement from taking NVNM supplements. Overall, over 53% of consumer's responses showed that no change was noticed from taking NVNM supplements.

CONCLUSIONS

Although the most commonly reported responses by those noticing change from NVNM supplement use were improved mobility and less joint pain, over half of the responses indicated that they did not feel any benefit from taking supplements, yet continued to purchase and take them. Communication of NVNM supplement use to their physician was low. More studies are needed to investigate what influences the decision to continue supplement use regardless of the lack of efficacy, considerable cost, and potential risks.

The impact of folic acid fortification of enriched grains on an elderly population: the New Mexico Aging Process Study

Fortification of enriched grains with synthetic folic acid is a potential concern for the elderly population who is at higher risk for Vitamin B12 deficiency. Consuming excess amounts of naturally occurring folate or synthetic folic acid can precipitate a deficiency of Vitamin B12, resulting in neurological damage. The purpose of this study was to determine the increase in folate intake in an elderly population due to the fortification of enriched grains. Three-day diet records of 320 participants (average age 76.8 years) were evaluated for total folate intake from food and supplements before and after the fortification of enriched grains. There was a significant mean daily folate intake increase of 63.8 microg due to fortification (p < 0.0001), raising the intake of total folate to 359 microg (89.8% of RDA). Supplements containing folic acid were consumed by 66% of the participants, raising the average total folate intake of supplement users to 793 microg per day. Only 5 participants exceeded the UL of 1,000 microg folic acid per day, with all 5 of these individuals consuming more than 1,000 microg folic acid per day from supplements alone. Folic acid fortification of grains does not appear to have increased the risk of excess folic acid in this population.

Sarcopenia: current perspectives

The development of sarcopenia is a complex multi-factorial process which begins in mid-life and accelerates after the age of 75 years. Although exercise, nutritional supplementation, hormone replacement and pro-inflammatory cytokine therapy may improve health status and reduce mortality, a better understanding of the complex interactions between these factors are needed. This review will focus on current information regarding the roles that physical activity, hormonal changes, energy intake, oxidative stress, and inflammatory processes play on the development and progression of sarcopenia.

Increased pulsatility, process irregularity, and nocturnal trough concentrations of growth hormone in amenorrheic compared to eumenorrheic athletes

Amenorrheic athletes exhibit a spectrum of neuroendocrine disturbances, including alterations in the GH-insulin-like growth factor I (IGF-I) axis. Whether these changes are due to exercise or amenorrhea is incompletely characterized. The present study investigates spontaneous (overnight) and exercise-stimulated GH secretion and associated IGF-binding proteins (IGFBPs) in amenorrheic (AA; n = 5), and eumenorrheic athletes ( n = 5) matched for age, percent body fat (dual energy x-ray absorptiometry), training history, and maximal oxygen consumption. Each volunteer participated in two hospital admissions consisting of a 50-min submaximal exercise bout (70% maximal oxygen consumption) and an 8-h nocturnal sampling period. Deconvolution analysis of serum GH concentration time series revealed increases in the half-life of GH (60%) and the number of secretory bursts (85%) as well as a decrease in their half-duration (50%) and the mass of GH secreted per pulse (300%) in the AA cohort. Time occupancy at elevated trough GH concentrations was significantly increased, and GH pulsatility (approximate entropy) was more irregular in the AA group. During exercise, AA exhibited a reversal of the normal relationship between IGF-I and GH, and a 4- to 5-fold blunting of stimulated peak and integrated GH secretion. Fasting levels of plasma IGF-I, IGFBP-3, and IGFBP-1 appeared to be unaffected by menstrual status. In ensemble, this phenotype of GH release in amenorrheic athletes suggests disrupted neuroregulation of episodic GH secretion, possibly reflecting decreased somatostinergic inhibition basally, and reduced GHRH output in response to exercise compared with eumenorrheic athletes. Accordingly, we postulate that the amenorrheic state, beyond the exercise experience per se, alters the neuroendocrine control of GH output in amenorrheic athletes.

Age-related changes in sex hormones affect the sex difference in serum leptin independently of changes in body fat

Serum leptin concentrations are highly correlated with body fatness, but there is considerable variability among individuals after adjusting for differences in body fatness. Theoretically, sex hormone levels may influence serum leptin, since the levels are higher in women than in men independently of body fat. Increasing old age is associated with decreases in serum sex hormone concentrations and changes in body fatness that may independently alter serum leptin concentrations. In a cross-sectional sample of 106 men and 166 women aged 62 to 98 years, serum leptin adjusted for total body fat had a significant positive association with age in men and a nonsignificant negative association with age in women. Serum testosterone had a significant negative association with serum leptin in men after adjusting for total body fat, the fasting insulin resistance index (FIRI), and sex hormone-binding globulin (SHBG). In a longitudinal sample of 22 elderly men and 52 women, serum leptin levels increased significantly over a 14-year period in men, but not in women. Increases in serum leptin were significantly associated with decreases in serum testosterone but not with changes in the body mass index (BMI) in men. In contrast, changes in leptin were associated with changes in the BMI but not with changes in serum estrone in women. These results suggest that differences among men and changes with age in serum leptin are associated with circulating levels of testosterone. Elderly men become progressively "hyperleptinemic" with age regardless of changes in body fatness, possibly due to decreasing testosterone levels.

Predictors of skeletal muscle mass in elderly men and women

BACKGROUND

Elderly men and women lose muscle mass and strength with increasing age. Decreased physical activity, hormones, malnutrition and chronic disease have been identified as factors contributing to this loss. There are few data, however, for their multivariate associations with muscle mass and strength. This study analyzes these associations in a cross-sectional sample of elderly people from the New Mexico Aging Process Study.

METHODS

Data collected in 1994 for 121 male and 180 female volunteers aged 65-97 years of age enrolled in The New Mexico Aging Process Study were analyzed. Body composition was measured using dual energy X-ray absorptiometry; dietary intake from 3 day food records; usual physical activity by questionnaire; health status from annual physical examinations; and serum testosterone, estrone, sex-hormone binding globulin (SHBG), and insulin-like growth factor (IGF1) from radioimmunoassays of fasting blood samples. Statistical analyses included partial correlation and stepwise multiple regression.

RESULTS

The muscle mass and strength (adjusted for knee height) decreased with increasing age in both sexes. The muscle mass was significantly associated with serum free-testosterone, physical activity, cardiovascular disease, and IGF1 in the men. In the women, the muscle mass was significantly associated with total fat mass and physical activity. Age was not associated significantly with muscle mass after controlling for these variables. Grip strength was associated with age independent of muscle mass in both sexes. Estrogen (endogenous and exogenous) was not associated with muscle mass or strength in women.

CONCLUSIONS

Age-related loss of muscle mass and strength occurs in relatively healthy, well-nourished elderly men and women and has a multifactorial basis. Sex hormone status is an important factor in men but not in women. Physical activity is an important predictor of muscle mass in both sexes.

Serum leptin in elderly people: associations with sex hormones, insulin, and adipose tissue volumes

OBJECTIVE

There are few data for associations of serum leptin with body fat, fat distribution, sex hormones, or fasting insulin in elderly adults. We hypothesized that the sex difference in serum leptin concentrations would disappear after adjustment for subcutaneous, but not visceral body fat. Serum leptin would not be associated with sex hormone concentrations or serum fasting insulin after adjusting for body fat and fat distribution.

RESEARCH METHODS AND PROCEDURES

Subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) volumes were measured using magnetic resonance imaging in a cross-sectional sample of 56 nondiabetic, elderly men and women aged 64 years to 94 years. Serum leptin, sex hormones (testosterone and estrone), sex hormone-binding globulin, and fasting insulin were also measured. Nine women were taking hormone replacement, and five men were clinically hypogonadal.

RESULTS

Leptin was significantly associated with both SAT and VAT in each sex. Adjustment for SAT reduced the sex difference in leptin by 56%, but adjustment for VAT increased the difference by 25%. Leptin was not associated with serum estrone or hormone replacement therapy in the women, but had a significant, negative association with testosterone in the men that was independent of SAT, but not VAT. Leptin was significantly associated with fasting insulin in both sexes independent of age, sex hormones, sex hormone-binding globulin, VAT and SAT.

DISCUSSION

Sex difference in serum leptin is partly explained by different amounts of SAT. Studies including both men and women should adjust for SAT rather than total body fat that includes VAT. The sex difference in serum leptin is not due to estrogen, but may be partly explained by testosterone. Testosterone is negatively associated with leptin in men, but the association is confounded with VAT. Leptin is associated with fasting insulin in nondiabetic elderly men and women independent of body fat, fat distribution, or sex hormones.

Clinical outcomes of newborn screening for cystic fibrosis

AIM

To determine how early diagnosis of cystic fibrosis, using neonatal screening, affects long term clinical outcome.

METHODS

Fifty seven children with cystic fibrosis born before neonatal screening was introduced (1978 to mid 1981) and a further 60 children born during the first three years of the programme (mid 1981 to 1984), were followed up to the age of 10. The cohorts were compared on measures of clinical outcome, including height, weight, lung function tests, chest x-ray picture and Shwachman score.

RESULTS

Age and sex adjusted standard deviation scores (SDS) for height and weight were consistently higher in children screened for cystic fibrosis than in those born before screening. At 10 years of age, average differences in SDS between groups were 0.4 (95% CI -0.1, 0.8) for weight and 0.3 (95% CI -0.1, 0.7) for height. This translates to an average difference of about 2.7 cm in height and 1.7 kg in weight. Mean FEV1 and FVC (as percentage predicted) were significantly higher in the screened cohort at 5 and 10 years of age, with an average difference of 9.4% FEV1 (95% CI 0.8, 17.9) and 8.4% FVC (95% CI 1.8, 15.0) at 10 years. Chest x-ray scores were not different between the groups at any age, but by 10 years screened patients scored an average 5.3 (95% CI 1.2, 9.4) points higher on the Shwachman score.

CONCLUSION

Although not a randomised trial, this long term observational study indicates that early treatment made possible by neonatal screening may be important in determining subsequent clinical outcomes for children with cystic fibrosis. For countries contemplating the introduction of neonatal screening for cystic fibrosis, its introduction to some areas in a cluster randomised design will permit validation of studies performed to date.

Effects of estradiol on substrate turnover during exercise in amenorrheic females

The purpose of this investigation was to determine the effects of transdermal estradiol (E2) replacement on substrate utilization during exercise. Amenorrheic females (N = 6) performed three exercise trials following 72 h of placebo (C 72) and 72 and 144 h of medicated transdermal estradiol (E2) treatment (E2 72 and E2 144). Exercise involved 90 min of treadmill running at 65% VO2max followed by timed exercise to exhaustion at 85% VO2max. Resting blood samples were obtained for glucose, insulin, free fatty acids (FFA), and E2. Exercise blood samples were obtained for E2, lactate, epinephrine, and norepinephrine. Rates of appearance and disposal were calculated for glucose and glycerol using a primed, continuous infusion of [6,6-2H] glucose and [2H5] glycerol. Medicated transdermal placement increased E2 significantly at rest, before exercise (35.03 +/- 12.3, 69.5 +/- 20.1, and 73.1 +/- 31.6 pg.mL-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Resting FFA increased significantly following E2 treatment (0.28 +/- 0.16, 0.41 +/- 0.27, and 0.40 +/- 0.21 mmol.L-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Glucose Ra was significantly decreased during exercise as a result of E2 replacement (21.9 +/- 7.7, 18.9 +/- 6.2, and 18.9 +/- 5.6 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). Average glucose Rd also decreased during exercise as a result of E2 replacement (21.3 +/- 7.8, 18.5 +/- 6.4, and 18.6 +/- 5.8 mumol.kg-1.min-1 for the C 72, E2 72, and E2 144 trials, respectively, P < 0.05). However, the estimated relative contribution of plasma glucose and muscle glycogen to total carbohydrate oxidation was similar among the trials. Epinephrine values were significantly lower late in exercise during the E2 72 and E2 144 trials, compared with the C 72 trial (P < 0.05). These results indicate that elevated E2 levels can alter glucose metabolism at rest and during moderate intensity exercise as a result of decreased gluconeogenesis, epinephrine secretion, and/or glucose transport.

Prolonged efficacy of short acting insulin Lispro in combination with human ultralente in insulin-dependent diabetes mellitus

Insulin Lispro is a newly FDA approved analog of human insulin that exhibits rapid absorption and a short duration of action after sc injection. Although Lispro insulin improves immediate postprandial glycemia compared to Regular insulin, long term trials of Lispro insulin have not shown improvement in overall glycemic control, as determined by glycosylated hemoglobin. We hypothesize that this lack of improvement is attributable to the development of late postprandial hyperglycemia secondary to a waning of Lispro insulin's effect in conjunction with continued meal absorption. This study was designed to evaluate the duration of Lispro-induced reductions in plasma glucose after a standardized meal when Lispro insulin is incorporated into a regimen typically employed in insulin-dependent diabetes mellitus. After establishment of euglycemia overnight, 12 healthy IDDM patients received human Ultralente insulin (0.2 U/kg) alone and in combination with each of the following treatments in random sequence immediately before ingesting a 750-Cal American Diabetes Association breakfast: 1) 0.15 U/kg human Regular insulin (Regular 0.15 group), 2) 0.15 U/kg Lispro insulin (Lispro 0.15 group), 3) 0.1 U/kg Lispro insulin (Lispro 0.1 group), and 4) an equimolar (1:1) mixture of Lispro and Regular insulins (0.15 U/kg; 1:1 Mix group). Glucose and hormonal parameters were assessed for 8 h after the meal. Peak postprandial glucose was increased in the Regular insulin group compared to that in all groups that incorporated Lispro insulin (P < 0.001). Glucose area under the curve (AUC) was decreased in the Lispro 0.15 group compared to that in the Lispro 0.1 group, and glucose AUC was decreased in the Lispro 0.15 and 1:1 Mix groups compared to that in the group given Regular insulin (P < 0.001). Mean plasma glucose concentrations during the final hour of study were increased in the Ultralente group compared with those in all other treatment groups and were increased in the Lispro 0.1 group compared with those in the Regular, Lispro 0.15, and 1:1 Mix groups (P < 0.05). Insulin AUC was significantly reduced in the Lispro 0.1 group compared to those in all other short acting insulin groups (P < 0.001), and time to peak insulin was more rapid in the two Lispro groups than those in all other treatment groups (P < 0.01). The glucagon response was significantly greater in the Ultralente group compared to those with all other treatments. There was no difference in the development of hypoglycemia between the groups. This study demonstrates that the reductions in plasma glucose effected by Lispro insulin are consistent and stable for 8 h after meal ingestion when Lispro insulin is used in combination with human Ultralente insulin. These findings suggest that improvement in overall glycemia, as assessed by glycosylated hemoglobin, may be achievable with Lispro insulin if adequate doses are administered.

Body protein in prepubertal children with phenylketonuria

OBJECTIVE

To assess body protein and protein deposition in prepubertal children with phenylketonuria (PKU).

DESIGN

Cross-sectional study with nested longitudinal cohort.

SETTING

A tertiary referral paediatric hospital.

SUBJECTS

37 PKU patients (3.9-11.0 years) and 27 unselected healthy controls (4.0-11.5 years) of whom 29 PKU patients and 17 controls were followed longitudinally.

INTERVENTIONS

All had measurements of height, weight, body fat and total body nitrogen (TBN) by neutron capture analysis; PKU patients and their unaffected siblings (n = 16) also had measurements of four day weighed food record and plasma amino acids by HPLC.

RESULTS

The children with PKU compared with the controls were significantly shorter (height SD score -0.42 +/- 0.89 vs 0.17 +/- 0.94, respectively, P < 0.02) and had a lower TBN (575 +/- 200 vs 710 +/- 215g, respectively, P < 0.02). TBN in the controls was significantly correlated with lean body mass (LBM), weight, height and age (r = 0.97, 0.95, 0.95, 0.88, respectively, P < 0.001). The children with PKU had significantly lower TBN when predicted from LBM, weight and age (93%, 92%, 92% of predicted, respectively), but normal TBN predicted from height (102% of expected). The annual accretion of nitrogen was similar for the PKU and controls (86 +/- 45 and 77 +/- 58 g/y, respectively). There was no difference between the two groups in protein intake or plasma amino acids except for phenylalanine.

CONCLUSION

The children with PKU had a deficit in height and body protein despite a normal to higher accretion of protein. If the deficit occurs early in life, amino acid supplementation and other nutritional practices used at this time need to be reviewed.

Resting energy expenditure in children with phenylketonuria

Reports have suggested that children with phenylketonuria (PKU) weigh more compared with reference data. We found lower body protein and bone mineral density in children with PKU. These children may have a predisposition becoming overweight because of an alteration in body composition, which may lower resting energy expenditure (REE). REE was measured in 30 (15 males, 15 females) children with PKU (aged 9.6 +/- 2.9 y) and in 65 (23 males, 42 females) control children (aged 11.2 +/- 3.1 y). There was a comparable range in body fat within each group (control group: 11-34%; PKU group: 10-34%). The mean REE was similar between the male and female children with PKU (5300 +/- 757 and 4703 +/- 1024 kJ/24 h, respectively) and the control subjects (5306 +/- 969 and 5164 +/- 701 kJ/24 h, respectively). The children with PKU had an REE similar to that predicted from control data (males 102.1 +/- 7.8% of predicted and females 100.2 +/- 8.5% of predicted). This study found no evidence of a reduced REE or of increased weight in children with PKU.

Hepatobiliary disease in cystic fibrosis patients with pancreatic sufficiency

Focal and multilobular biliary cirrhosis are considered pathognomonic of cystic fibrosis (CF) and almost invariably have been reported in patients with steatorrhea. In contrast, patients with pancreatic sufficiency and normal absorption are considered less likely to develop liver or biliary tract problems. The authors report three patients with CF and pancreatic sufficiency, presenting with recurrent abdominal pain (unrelated to pancreatitis). All had common bile duct disease, one with multilobular cirrhosis and portal hypertension. Pancreatic sufficiency was proven by quantitative pancreatic stimulation tests, 3-day fecal fat analyses, and serum pancreatic isoamylases. All three patients had mild lung disease. Two were homozygous for the common delta F508 mutation, and the other, a delta F508 compound heterozygote. Hepatobiliary structure and function were determined by serial hepatobiliary scintigraphy, percutaneous transhepatic cholecystography, and biochemical liver function tests. Patients 1 and 3 had mild hepatomegaly, normal liver biochemistry, and distal common bile duct strictures. Patient 2 had a firm nodular liver with splenomegaly, abnormal liver biochemistry, and a cholangiographic appearance of sclerosing cholangitis. All have undergone operative treatment for persistent abdominal pain. These cases confirm the occurrence of common bile duct pathology and liver disease in patients with CF and pancreatic sufficiency. They demonstrate that liver and biliary tract disease can occur independently of the underlying disease severity and the presence of steatorrhea. Further, they suggest that obstruction of the biliary tract may be an additional factor in the evolution of liver disease in CF.

Decreased bone mineral density in children with phenylketonuria

Previous studies have suggested that children with phenylketonuria (PKU) have a reduction in bone mineralization compared with control subjects. To investigate this, bone mineral density (BMD) of the total body (TBMD) was measured in 32 prepubertal children with PKU and in 95 age-matched control subjects. Spine bone mineral density (SBMD) was also recorded in a subset, 24 with PKU and 55 control subjects. The effect of dietary intake on bone mass was assessed in 30 of the children with PKU and in 12 control subjects. In the children with PKU, TBMD and SBMD were significantly lower than in the control subjects after adjustment for height and weight (P = 0.03 and P = 0.003, respectively). The children with PKU had a higher intake of calcium (P < 0.0001), phosphorus (P = -0.0002), and magnesium (P < 0.0001), suggesting that their lower BMD occurred despite an adequate diet based on current recommendations. Further study is needed to establish the cause of this deficit in bone mass and the benefit of additional nutritional support to reverse this problem.

Nitrogen deposition in malnourished children with cystic fibrosis

To determine the protein nutritional status of 21 malnourished children with cystic fibrosis (CF), total body nitrogen (TBN) was measured and the results were compared with 21 control subjects. CF patients demonstrated a lower TBN (P less than 0.001). When matched for height (n = 10) or bone age (n = 13), the CF patients still had a depressed TBN/height or TBN/lean body mass (P less than 0.05). To assess nitrogen deposition during nutritional rehabilitation, repeat TBN measurements were performed on the 21 CF patients. Nitrogen deposition ranged from -230 to 550 g/y and correlated with weight velocity (r = 0.78, P less than 0.001). Increased nitrogen deposition (greater than 150 g/y) was generally associated with normal height gain (height velocity SD score greater than -2.00) and weight gain (greater than 2.0 kg/y). Decreased nitrogen deposition was associated with poor weight gain but did not preclude normal linear growth. These data suggest an important role for TBN estimations in defining protein nutritional status in children and indicate that skeletal growth can continue in the presence of minimal nitrogen deposition.

Nutritional status, growth and development in children undergoing intensive treatment for cystic fibrosis

Dietary intakes were measured over a period of 5 days in 36 malnourished and 36 well-nourished patients with cystic fibrosis. Both energy and protein intakes were significantly less in the malnourished patients for the two age groups studied: 4-9.99 years (p less than 0.01 for both parameters), and 10-16 years (p less than 0.05 and p less than 0.01, respectively). In both age groups and both patient groups, average protein intakes were well in excess of the recommended daily intake, but energy intake in the malnourished patients was below the recommended daily intake. Nutritional supplementation of 10 malnourished patients with a polymeric formula, infused overnight via a gastrostomy tube, resulted in a seven-fold increase in weight gain (p less than 0.001) and a doubling of linear growth velocity (p less than 0.01) over a period of 18 months, compared to the 18 months prior to gastrostomy feeding. Measurements of total body nitrogen in eight of these patients demonstrated a 38% increase in body nitrogen content over 12 months, indicating a replenishment of the protein deficit.

Pancreatic function in infants identified as having cystic fibrosis in a neonatal screening program

The use of the dried-blood immunoreactive-trypsin assay for the detection of cystic fibrosis in newborns has been questioned on the grounds that it may fail to identify patients with enough pancreatic function to have normal fat absorption. To investigate this possibility, we assessed pancreatic function in 78 patients identified in a neonatal screening program as having cystic fibrosis. The diagnosis of cystic fibrosis was confirmed by abnormal results on a sweat chloride test. The results of measurements of fecal fat excretion, pancreatic-stimulation tests, and estimations of the serum level of pancreatic isoamylase indicated that 29 of the 78 children (37 percent) had substantial preservation of pancreatic function. These children (median age, four years) had growth that was close to normal and comparable to growth in children with severe pancreatic insufficiency who received oral enzyme therapy. Pancreatic insufficiency subsequently developed in 6 of the 29 patients, at 3 to 36 months of age. We conclude that the serum immunoreactive-trypsin assay used in neonatal screening programs identifies patients with cystic fibrosis who have sufficient pancreatic function to have normal fat absorption and that a substantial proportion of infants identified as having cystic fibrosis are in this category.

Body composition response to exogenous GH during training in highly conditioned adults

The effects of biosynthetic methionyl-human growth hormone (met-hGH) on body composition and endogenous secretion of growth hormone (GH) and insulin-like growth factor I (IGF-I) were studied in eight well-trained exercising adults between 22 and 33 yr of age. By the use of double-blind procedures, met-hGH (2.67 mg/0.5 ml diluent, 3 days/wk) and bacteriostatic water (placebo, 0.5 ml, 3 days/wk) were administered in a repeated-measures design that counterbalanced treatment order. Duration of each treatment was 6 wk. Subjects trained with progressive resistance exercise throughout and were maintained on a high-protein diet monitored by extensive compositional analyses of daily dietary intake records. Hydrodensitometry revealed that met-hGH significantly decreased percent body fat (%fat) and increased fat-free weight (FFW) and FFW/fat weight (FW), whereas the placebo treatment did not change any of these measures. Changes in FFW/FW correlated with the relative dose of met-hGH but did not correlate with either the peak GH response to L-dopa/arginine stimulation or IGF-I levels obtained after treatment with placebo. There were no differences between treatments in the dietary intakes of total kilocalories, protein, carbohydrates, and fat. Mean IGF-I levels were elevated after treatment with met-hGH compared with postplacebo levels. After treatment with met-hGH, five of seven subjects had a suppressed GH response to stimulation from either L-dopa/arginine or submaximal exercise. We conclude that supraphysiological doses of met-hGH will alter body composition in exercising adults in a relative dose-dependent manner and that such treatment may suppress endogenous release of GH in some individuals.

Liver disease and common-bile-duct stenosis in cystic fibrosis

To determine the incidence of common-bile-duct lesions and their relation to liver disease in cystic fibrosis, we performed hepatobiliary scanning in 50 of 61 patients with cystic fibrosis who had hepatomegaly, abnormal liver function, or both and in 31 of 92 patients with cystic fibrosis who did not have hepatomegaly or abnormal liver function. Ninety-six percent of the patients with liver disease had evidence of biliary tract obstruction, which was defined cholangiographically as a stricture of the distal common bile duct in the majority of cases. All the patients without liver disease had normal intrahepatic and common-duct excretion of tracer. Abdominal pain was significantly more common in patients with common-duct obstruction (P less than 0.001), and enlarged gallbladders occurred only in such patients. Since fasting levels of serum bile acids were elevated in nearly half these patients, irrespective of the severity of their liver disease, serum bile acids may be markers of the severity of the common-duct lesion. We conclude that strictures of the distal common bile duct are common in patients with cystic fibrosis and liver disease. This association requires further study, since surgical relief of common-duct obstruction may prevent or ameliorate the hepatic complications of cystic fibrosis.