Short-term body weight fluctuations in older well-hydrated hospitalised patients

Malnutrition in hospitalized adults in the United States, 2016-2019

BACKGROUND

Malnutrition in hospitalized patients is associated increased length of stay, cost, readmission, and death. No recent studies have examined trends in prevalence or outcomes of hospitalized patients with a diagnosis of malnutrition.

OBJECTIVES

To study the prevalence of malnutrition diagnostic codes and associated hospital outcomes in the United States between 2016 and 2019.

METHODS

We conducted a retrospective trends study to identify use of malnutrition codes in hospitalizations in the National Inpatient Sample between 2016 and 2019. We used direct standardization by logistic regression to adjust outcomes of percutaneous gastrostomy tube placement, mechanical ventilation, and death for age, Gagne comorbidity score, and sex. We then used linear regression to test for trends over time by malnutrition type.

RESULTS

Across all hospitalizations, codes for diagnoses of nonsevere malnutrition and severe malnutrition were present in 3.7% and 4.1% of hospitalizations, respectively. Codes for any malnutrition increased over time, from 6.6% in 2016 to 8.6% in 2018 (p = .03). Codes for severe malnutrition increased from 3.3% to 4.7% (p = .01). Among hospitalizations with coded severe malnutrition diagnoses, there was a statistically significant decrease in adjusted rate of death over time (-0.54% per year, p = .03) which was not seen in hospitalizations without coded malnutrition diagnoses.

CONCLUSIONS

Use of malnutrition diagnosis codes increased significantly from 2016 to 2019. During this time, mortality among hospitalizations with a diagnosis code for severe malnutrition decreased. Though the increased prevalence of malnutrition codes may represent a change in the clinical characteristics of hospitalized patients, the decline in mortality suggests some of the increase may be due to lower threshold for coding and assignment of the diagnosis to less ill patients.

Hydration Status Assessment in Older Patients

BACKGROUND

Hydration disturbances are common in old age: the reported prevalence of dehydration in elderly patients ranges from 19% to 89%, depending on the definition and the population in question. However, the clinical assessment of patients' hydration status is difficult. In this review, we discuss the diagnostic value of currently used methods that may or may not be suitable for assessing older patients' hydration status.

METHODS

We conducted a selective literature search for relevant studies concerning patients aged 65 and above. Of the 355 articles retrieved by the initial search, a multistep selection process yielded 30 that were suitable for inclusion in this review.

RESULTS

107 different methods for the diagnostic assessment of dehydration in older persons were evaluated on the basis of the reviewed publications. High diagnostic value, especially for the determination of hyperosmolar dehydration, was found for serum osmolality, serum sodium concentration, inferior vena cava ultrasonography, a history (from the patient or another informant) of not drinking between meals, and axillary dryness. On the other hand, a variety of clinical signs such as a positive skin turgor test, sunken eyes, dry mouth, tachycardia, orthostatic dysregulation, and dark urine were found to be of inadequate diagnostic value.

CONCLUSION

Only five of the 107 methods considered appear to be suitable for determining that a patient is dehydrated. Thus, the available scientific evidence indicates that all clinicians should critically reconsider their own techniques for assessing hydration status in elderly patients. To optimize the clinical assessment of patients' hydration status, there seems to be a need for the rejection of unsuitable methods in favor of either newly developed criteria or of a combination of the best criteria already in use.

INTERmittent FASTing in people with insulin-treated type 2 diabetes mellitus - the INTERFAST-2 study protocol

AIM

Intermittent fasting, a dietary intervention of alternate eating and fasting, has gained popularity in people trying to lose weight. Intermittent fasting could provide an alternative to classic caloric restriction in people with type 2 diabetes mellitus. The aim of the study is to determine the impact of a 12-week intermittent fasting regimen compared with usual care in people with type 2 diabetes mellitus receiving insulin therapy.

METHODS

This open, single-centre, randomized controlled trial investigates participants with type 2 diabetes mellitus on insulin therapy and a glycated haemoglobin A1c (HbA1c) of ≥53 mmol/mol (≥7.0%) and a minimum insulin dose of 0.3 IU/kg body weight per day. Participants are randomized in a 1:1 ratio to either 12 weeks of intermittent fasting or the standard care group. All participants receive dietary counselling, continuous glucose monitoring, measurement of the resting metabolic rate, an oral glucose tolerance test, body composition measurement via dual-energy X-ray absorptiometry and stool samples for microbiome analyses at the beginning and at the end of the intervention. Two co-primary outcomes (analysed in hierarchical order) were chosen for the study: (i) the difference in the change of HbA1c from baseline to 12 weeks and (ii) the difference in the number of participants achieving a combined end point encompassing a body weight reduction of at least 2%, an insulin dose reduction of at least 10% and an absolute HbA1c reduction of at least 3 mmol/mol (0.3%) between the two groups.

Weight loss during neoadjuvant therapy for pancreatic cancer does not predict poor outcomes

BACKGROUND

Weight changes during neoadjuvant chemotherapy (NAC) for pancreatic cancer (PDAC) are not well studied. We hypothesized that weight loss may predict poor outcomes.

METHODS

Weight change from NAC initiation to pancreatectomy was grouped: gain (≥5%), stable, and loss (≥5%). Pathologic, postoperative, and survival outcomes were compared.

RESULTS

95 patients were included: 31.6% lost weight, 58.9% maintained weight, and 9.5% gained weight. There were no differences in chemotherapeutic regimens. Median recurrence-free survival (RFS) and overall survival (OS) were similar between patients with stable weight and those who lost weight (RFS: 9.6vs14.0months; OS: 25.8vs26.7months). Among those who gained weight, RFS (29.5months) and OS (38.4months) were greater relative to the other weight categories. On multivariable regression, weight gain was associated with improved RFS compared to loss (HR = 0.16).

CONCLUSION

Most patients maintain or lose weight during NAC, and weight loss does not predict poor outcomes. Weight gain may predict improved RFS.

Frequency of Self-Weighing and Weight Change: Cohort Study With 10,000 Smart Scale Users

Background

Frequent self-weighing is associated with successful weight loss and weight maintenance during and after weight loss interventions. Less is known about self-weighing behaviors and associated weight change in free-living settings.

Objective

This study aimed to investigate the association between the frequency of self-weighing and changes in body weight in a large international cohort of smart scale users.

Methods

This was an observational cohort study with 10,000 randomly selected smart scale users who had used the scale for at least 1 year. Longitudinal weight measurement data were analyzed. The association between the frequency of self-weighing and weight change over the follow-up was investigated among normal weight, overweight, and obese users using Pearson’s correlation coefficient and linear models. The association between the frequency of self-weighing and temporal weight change was analyzed using linear mixed effects models.

Results

The eligible sample consisted of 9768 participants (6515/9768, 66.7% men; mean age 41.5 years; mean BMI 26.8 kg/m2). Of the participants, 4003 (4003/9768, 41.0%), 3748 (3748/9768, 38.4%), and 2017 (2017/9768, 20.6%) were normal weight, overweight, and obese, respectively. During the mean follow-up time of 1085 days, the mean weight change was –0.59 kg, and the mean percentage of days with a self-weigh was 39.98%, which equals 2.8 self-weighs per week. The percentage of self-weighing days correlated inversely with weight change, r=–0.111 (P<.001). Among normal weight, overweight, and obese individuals, the correlations were r=–0.100 (P<.001), r=–0.125 (P<.001), and r=–0.148 (P<.001), respectively. Of all participants, 72.5% (7085/9768) had at least one period of ≥30 days without weight measurements. During the break, weight increased, and weight gains were more pronounced among overweight and obese individuals: 0.58 kg in the normal weight group, 0.93 kg in the overweight group, and 1.37 kg in the obese group (P<.001).

Conclusions

Frequent self-weighing was associated with favorable weight loss outcomes also in an uncontrolled, free-living setting, regardless of specific weight loss interventions. The beneficial associations of regular self-weighing were more pronounced for overweight or obese individuals.

A systematic review of the methodology used to study weight change among young adults attending college

INTRODUCTION

Young adulthood is a sensitive developmental period that is high-risk for weight gain. Ample research has focused on weight gain among college students; however meta-analyses report <2 kg pooled estimates of weight gain, which is in the range of normal weight fluctuation, and there is disagreement in the literature regarding common predictors of weight gain. These limitations pose a major barrier to targeted obesity prevention efforts. The present study reviewed the literature assessing college weight gain with a focus on three methodological factors that could contribute to variability in the literature: 1) use of an evidence-supported definition of weight gain (>2 kg or ≥3%); 2) weight measurement protocols; and 3) including weight/BMI in analyses of predictors of weight change.

METHODS

Three databases were systematically searched. Studies were included in the review if the primary goal was to determine magnitude of weight change and/or test predictors of weight change during the academic year, and they reported weight at 2+ time points.

RESULTS

A total of 81 studies were included in the review. Most studies (90%; 73/81) did not use an evidence-supported definition of weight gain. Studies that used an evidence-supported definition reported estimates of gain among students who gained weight to be beyond the range of normal weight fluctuation (4.0-7.5 kg), and occurred in a subset (<32%) of participants. Studies that did not use an evidence-supported definition reported weight gain to be 2.0-4.5 kg, and occurred in the majority >50% of students. Most studies that measured height and weight (71%; 42/59) did not use a fasting protocol and the majority (63%; 37/59) did not conduct measurements at the same time of day. A higher percentage of studies that used a standardized measurement protocol reported weight change >2 kg (44% vs 20%). A lower percentage of studies that used a standardized measurement protocol had substantial variability in weight change estimates (50% vs 69%). The majority of studies that tested predictors of weight gain (74%; 42/57) included weight/BMI as a covariate in analyses.

CONCLUSIONS

The body of literature examining weight change among college students suffers from limitations that may have contributed to overestimations in the percent of students who gain weight, and simultaneous underestimations of the magnitude of weight gain among those who gain weight. Weight gain may be limited to approximately 30% of students in a sample, and weight gain among this subset of students may be substantial (>4 kg). Going forward, use of both an evidence-supported weight gain definition and fasting measurement protocol will likely enhance accuracy in characterizing weight gain among college students, as well as improve researchers' ability to detect important predictors of weight gain.

Composition of two-week change in body weight under unrestricted free-living conditions

The composition of weight change has a large impact on energy balance calculations. Composition of long-term weight change interventions is well-documented, but information on short-term weight change under unrestricted free-living conditions is limited. The composition and energy density of the changes in body weight during 2-week free-living conditions were analyzed in adults from two cohorts: cohort 1 (n = 24) included participants from the reproducibility subset of the Observing Protein and Energy Nutrition study; cohort 2 (n = 22) included participants who were studied under free-living conditions in an ongoing study in the Chicago area. Change in body weight, total body water (TBW) by stable isotope dilution (cohort 1), and fat mass (FM) and fat-free mass (FFM) by serial DXA (cohort 2) were measured. To determine the fractional composition of the change in body weight we analyzed the linear associations between changes in body weight and changes in body composition. In the combined dataset, the average change in body weight (0.26 ± 1.2 kg) was consistent with being in energy balance. Average change in body weight was associated with the change in TBW (P < 0.0001) in cohort 1 and the change in FFM (P = 0.0002) in cohort 2. A unit change in body weight was composed of 84% change in FFM in the combined dataset indicating that 2-week fluctuation in body weight is largely composed of FFM The energy density of 1-3 kg short-term changes in body weight averaged 2380 kcal/kg.

Which Frail Older People Are Dehydrated? The UK DRIE Study

BACKGROUND

Water-loss dehydration in older people is associated with increased mortality and disability. We aimed to assess the prevalence of dehydration in older people living in UK long-term care and associated cognitive, functional, and health characteristics.

METHODS

The Dehydration Recognition In our Elders (DRIE) cohort study included people aged 65 or older living in long-term care without heart or renal failure. In a cross-sectional baseline analysis, we assessed serum osmolality, previously suggested dehydration risk factors, general health, markers of continence, cognitive and functional health, nutrition status, and medications. Univariate linear regression was used to assess relationships between participant characteristics and serum osmolality, then associated characteristics entered into stepwise backwards multivariate linear regression.

RESULTS

DRIE included 188 residents (mean age 86 years, 66% women) of whom 20% were dehydrated (serum osmolality >300 mOsm/kg). Linear and logistic regression suggested that renal, cognitive, and diabetic status were consistently associated with serum osmolality and odds of dehydration, while potassium-sparing diuretics, sex, number of recent health contacts, and bladder incontinence were sometimes associated. Thirst was not associated with hydration status.

CONCLUSIONS

DRIE found high prevalence of dehydration in older people living in UK long-term care, reinforcing the proposed association between cognitive and renal function and hydration. Dehydration is associated with increased mortality and disability in older people, but trials to assess effects of interventions to support healthy fluid intakes in older people living in residential care are needed to enable us to formally assess causal direction and any health benefits of increasing fluid intakes.

Water-loss (intracellular) dehydration assessed using urinary tests: how well do they work? Diagnostic accuracy in older people

BACKGROUND

Water-loss dehydration (hypertonic, hyperosmotic, or intracellular dehydration) is due to insufficient fluid intake and is distinct from hypovolemia due to excess fluid losses. Water-loss dehydration is associated with poor health outcomes such as disability and mortality in older people. Urine specific gravity (USG), urine color, and urine osmolality have been widely advocated for screening for dehydration in older adults.

OBJECTIVE

We assessed the diagnostic accuracy of urinary measures to screen for water-loss dehydration in older people.

DESIGN

This was a diagnostic accuracy study of people aged ≥65 y taking part in the DRIE (Dehydration Recognition In our Elders; living in long-term care) or NU-AGE (Dietary Strategies for Healthy Ageing in Europe; living in the community) studies. The reference standard was serum osmolality, and index tests included USG, urine color, urine osmolality, urine cloudiness, additional dipstick measures, ability to provide a urine sample, and the volume of a random urine sample. Minimum useful diagnostic accuracy was set at sensitivity and specificity ≥70% or a receiver operating characteristic plot area under the curve ≥0.70.

RESULTS

DRIE participants (women: 67%; mean age: 86 y; n = 162) had more limited cognitive and functional abilities than did NU-AGE participants (women: 64%; mean age: 70 y; n = 151). Nineteen percent of DRIE participants and 22% of NU-AGE participants were dehydrated (serum osmolality >300 mOsm/kg). Neither USG nor any other potential urinary tests were usefully diagnostic for water-loss dehydration.

CONCLUSIONS

Although USG, urine color, and urinary osmolality have been widely advocated for screening for dehydration in older adults, we show, in the largest study to date to our knowledge, that their diagnostic accuracy is too low to be useful, and these measures should not be used to indicate hydration status in older people (either alone or as part of a wider tranche of tests). There is a need to develop simple, inexpensive, and noninvasive tools for the assessment of dehydration in older people. The DRIE study was registered at www.researchregister.org.uk as 122273. The NU-AGE trial was registered at clinicialtrials.gov as NCT01754012.

Diagnostic accuracy of calculated serum osmolarity to predict dehydration in older people: adding value to pathology laboratory reports

OBJECTIVES

To assess which osmolarity equation best predicts directly measured serum/plasma osmolality and whether its use could add value to routine blood test results through screening for dehydration in older people.

DESIGN

Diagnostic accuracy study.

PARTICIPANTS

Older people (≥65 years) in 5 cohorts: Dietary Strategies for Healthy Ageing in Europe (NU-AGE, living in the community), Dehydration Recognition In our Elders (DRIE, living in residential care), Fortes (admitted to acute medical care), Sjöstrand (emergency room) or Pfortmueller cohorts (hospitalised with liver cirrhosis).

REFERENCE STANDARD FOR HYDRATION STATUS

Directly measured serum/plasma osmolality: current dehydration (serum osmolality>300 mOsm/kg), impending/current dehydration (≥295 mOsm/kg).

INDEX TESTS

39 osmolarity equations calculated using serum indices from the same blood draw as directly measured osmolality.

RESULTS

Across 5 cohorts 595 older people were included, of whom 19% were dehydrated (directly measured osmolality>300 mOsm/kg). Of 39 osmolarity equations, 5 showed reasonable agreement with directly measured osmolality and 3 had good predictive accuracy in subgroups with diabetes and poor renal function. Two equations were characterised by narrower limits of agreement, low levels of differential bias and good diagnostic accuracy in receiver operating characteristic plots (areas under the curve>0.8). The best equation was osmolarity=1.86×(Na++K+)+1.15×glucose+urea+14 (all measured in mmol/L). It appeared useful in people aged ≥65 years with and without diabetes, poor renal function, dehydration, in men and women, with a range of ages, health, cognitive and functional status.

CONCLUSIONS

Some commonly used osmolarity equations work poorly, and should not be used. Given costs and prevalence of dehydration in older people we suggest use of the best formula by pathology laboratories using a cutpoint of 295 mOsm/L (sensitivity 85%, specificity 59%), to report dehydration risk opportunistically when serum glucose, urea and electrolytes are measured for other reasons in older adults.

TRIAL REGISTRATION NUMBERS

DRIE: Research Register for Social Care, 122273; NU-AGE: ClinicalTrials.gov NCT01754012.

Clinical symptoms, signs and tests for identification of impending and current water-loss dehydration in older people

BACKGROUND

There is evidence that water-loss dehydration is common in older people and associated with many causes of morbidity and mortality. However, it is unclear what clinical symptoms, signs and tests may be used to identify early dehydration in older people, so that support can be mobilised to improve hydration before health and well-being are compromised.

OBJECTIVES

To determine the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs and tests to be used as screening tests for detecting water-loss dehydration in older people by systematically reviewing studies that have measured a reference standard and at least one index test in people aged 65 years and over. Water-loss dehydration was defined primarily as including everyone with either impending or current water-loss dehydration (including all those with serum osmolality ≥ 295 mOsm/kg as being dehydrated).

SEARCH METHODS

Structured search strategies were developed for MEDLINE (OvidSP), EMBASE (OvidSP), CINAHL, LILACS, DARE and HTA databases (The Cochrane Library), and the International Clinical Trials Registry Platform (ICTRP). Reference lists of included studies and identified relevant reviews were checked. Authors of included studies were contacted for details of further studies.

SELECTION CRITERIA

Titles and abstracts were scanned and all potentially relevant studies obtained in full text. Inclusion of full text studies was assessed independently in duplicate, and disagreements resolved by a third author. We wrote to authors of all studies that appeared to have collected data on at least one reference standard and at least one index test, and in at least 10 people aged ≥ 65 years, even where no comparative analysis has been published, requesting original dataset so we could create 2 x 2 tables.

DATA COLLECTION AND ANALYSIS

Diagnostic accuracy of each test was assessed against the best available reference standard for water-loss dehydration (serum or plasma osmolality cut-off ≥ 295 mOsm/kg, serum osmolarity or weight change) within each study. For each index test study data were presented in forest plots of sensitivity and specificity. The primary target condition was water-loss dehydration (including either impending or current water-loss dehydration). Secondary target conditions were intended as current (> 300 mOsm/kg) and impending (295 to 300 mOsm/kg) water-loss dehydration, but restricted to current dehydration in the final review.We conducted bivariate random-effects meta-analyses (Stata/IC, StataCorp) for index tests where there were at least four studies and study datasets could be pooled to construct sensitivity and specificity summary estimates. We assigned the same approach for index tests with continuous outcome data for each of three pre-specified cut-off points investigated.Pre-set minimum sensitivity of a useful test was 60%, minimum specificity 75%. As pre-specifying three cut-offs for each continuous test may have led to missing a cut-off with useful sensitivity and specificity, we conducted post-hoc exploratory analyses to create receiver operating characteristic (ROC) curves where there appeared some possibility of a useful cut-off missed by the original three. These analyses enabled assessment of which tests may be worth assessing in further research. A further exploratory analysis assessed the value of combining the best two index tests where each had some individual predictive ability.

MAIN RESULTS

There were few published studies of the diagnostic accuracy of state (one time), minimally invasive clinical symptoms, signs or tests to be used as screening tests for detecting water-loss dehydration in older people. Therefore, to complete this review we sought, analysed and included raw datasets that included a reference standard and an index test in people aged ≥ 65 years.We included three studies with published diagnostic accuracy data and a further 21 studies provided datasets that we analysed. We assessed 67 tests (at three cut-offs for each continuous outcome) for diagnostic accuracy of water-loss dehydration (primary target condition) and of current dehydration (secondary target condition).Only three tests showed any ability to diagnose water-loss dehydration (including both impending and current water-loss dehydration) as stand-alone tests: expressing fatigue (sensitivity 0.71 (95% CI 0.29 to 0.96), specificity 0.75 (95% CI 0.63 to 0.85), in one study with 71 participants, but two additional studies had lower sensitivity); missing drinks between meals (sensitivity 1.00 (95% CI 0.59 to 1.00), specificity 0.77 (95% CI 0.64 to 0.86), in one study with 71 participants) and BIA resistance at 50 kHz (sensitivities 1.00 (95% CI 0.48 to 1.00) and 0.71 (95% CI 0.44 to 0.90) and specificities of 1.00 (95% CI 0.69 to 1.00) and 0.80 (95% CI 0.28 to 0.99) in 15 and 22 people respectively for two studies, but with sensitivities of 0.54 (95% CI 0.25 to 0.81) and 0.69 (95% CI 0.56 to 0.79) and specificities of 0.50 (95% CI 0.16 to 0.84) and 0.19 (95% CI 0.17 to 0.21) in 21 and 1947 people respectively in two other studies). In post-hoc ROC plots drinks intake, urine osmolality and axillial moisture also showed limited diagnostic accuracy. No test was consistently useful in more than one study.Combining two tests so that an individual both missed some drinks between meals and expressed fatigue was sensitive at 0.71 (95% CI 0.29 to 0.96) and specific at 0.92 (95% CI 0.83 to 0.97).There was sufficient evidence to suggest that several stand-alone tests often used to assess dehydration in older people (including fluid intake, urine specific gravity, urine colour, urine volume, heart rate, dry mouth, feeling thirsty and BIA assessment of intracellular water or extracellular water) are not useful, and should not be relied on individually as ways of assessing presence or absence of dehydration in older people.No tests were found consistently useful in diagnosing current water-loss dehydration.

AUTHORS' CONCLUSIONS

There is limited evidence of the diagnostic utility of any individual clinical symptom, sign or test or combination of tests to indicate water-loss dehydration in older people. Individual tests should not be used in this population to indicate dehydration; they miss a high proportion of people with dehydration, and wrongly label those who are adequately hydrated.Promising tests identified by this review need to be further assessed, as do new methods in development. Combining several tests may improve diagnostic accuracy.

Body composition and morphological assessment of nutritional status in adults: a review of anthropometric variables

Evaluation of body composition is an important part of assessing nutritional status and provides prognostically useful data and an opportunity to monitor the effects of nutrition-related disease progression and nutritional intervention. The aim of this narrative review is to critically evaluate body composition methodology in adults, focusing on anthropometric variables. The variables considered include height, weight, body mass index and alternative indices, trunk measurements (waist and hip circumferences and sagittal abdominal diameter) and limb measurements (mid-upper arm and calf circumferences) and skinfold thickness. The importance of adhering to a defined measurement protocol, checking measurement error and the need to interpret measurements using appropriate population-specific cut-off values to identify health risks were highlighted. Selecting the optimum method for assessing body composition using anthropometry depends on the purpose (i.e. evaluating obesity or undernutrition) and requires practitioners to have a good understanding of both practical and theoretical limitations and to be able to interpret the results wisely.

Involuntary weight loss

Involuntary weight loss remains an important and challenging clinical problem, with a high degree of morbidity and mortality. Because of the frequency of finding a serious underlying diagnosis, clinicians must be thorough in assessment, keeping in mind a broad range of possible causes. Although prediction scores exist, they have not been broadly validated; therefore, clinical judgment remains ever essential.