BUN as an Independent Predictor of Post-Hospital-Discharge Mortality among Older Veterans.

BACKGROUND/OBJECTIVES: An elevated blood urea nitrogen (BUN) in known to be an important prognostic indicator in patients with end-stage heart or kidney disease or certain other life-threatening illnesses. However, it is less certain as to whether an elevated BUN is an independent predictor of long-term mortality risk in less seriously ill patients. To address this issue, we examined the relationship between BUN and long-term mortality after adjusting for potential confounders and other indicators of health status/disease severity, in a select population of older medically stable Veterans. DESIGN: Long-term prospective cohort study. SETTING: Outpatient follow-up of patients discharged from a recuperative care and rehabilitation unit (RCRU) of a Department of Veterans Affairs Community Living Center. PARTICIPANTS: 383 older Veterans (mean age = 78.6±7.6 years, 98% male, and 87% white) discharged alive and in stable medical condition. MEASUREMENTS: At discharge, each subject completed a comprehensive assessment and was then monitored as an outpatient for up to 9.3 years. Associations between blood urea nitrogen at RCRU discharge and mortality were identified utilizing Cox proportional hazards (PH) regression analyses adjusting for conditions known to confound this relationship. RESULTS: Within the follow-up period, 255 subjects (67%) died. In the unadjusted Cox PH model, a BUN ≥ 30 mg/dL was associated with a nearly 2-fold increased risk of mortality (hazard ratio 1.90, 95%CI 1.41 - 2.56). The association between BUN and long-term mortality remained highly significant after adjusting for potential confounders (hazard ratio 1.78, 95%CI 1.29 - 2.44). CONCLUSION: Our findings support BUN levels as an independent predictor of long-term mortality in older, medically stable Veterans. An elevated BUN may be reflective of global health status rather than solely an indicator of the severity of acute illness or unstable chronic disease.

Single-Arm Resistance Training Study to Determine the Relationship between Training Outcomes and Muscle Growth Factor mRNAs in Older Adults Consuming Numerous Medications and Supplements.

OBJECTIVES: Determine if the muscle mRNA levels of three growth factors (insulin-like growth factor-1 [IGF1], ciliary neurotropic factor [CNTF], and vascular endothelial growth factor-D [VEGFD]) are correlated with muscle size and strength gains from resistance exercise while piloting a training program in older adults taking medications and supplements for age-associated problems. DESIGN: Single-arm prospective study. SETTING: US Veterans Affairs hospital. PARTICIPANTS: Older (70±6 yrs) male Veterans (N=14) of US military service. INTERVENTION: Thirty-five sessions of high-intensity (80% one-rep max) resistance training including leg press, knee curl, and knee extension to target the thigh muscles. MEASUREMENTS: Vastus lateralis biopsies were collected and body composition (DEXA) was determined pre- and post-training. Simple Pearson correlations were used to compare training outcomes to growth factor mRNA levels and other independent variables such as medication and supplement use. RESULTS: Average strength increase for the group was ≥ 25% for each exercise. Subjects averaged taking numerous medications (N=5±3) and supplements (N=2±2). Of the growth factors, a significant correlation (R>0.7, P≤0.003) was only found between pre-training VEGFD and gains in lean thigh mass and extension strength. Mass and strength gains were also correlated with use of α-1 antagonists (R=0.55, P=0.04) and pre-training lean mass (R=0.56, P=0.04), respectively. CONCLUSIONS: Muscle VEGFD, muscle mass, and use of α-1 antagonists may be predisposing factors that influence the response to training in this population of older adults but additional investigation is required to determine if these relationships are due to muscle angiogenesis and blood supply.

Protein-energy undernutrition and the risk of mortality within one year of hospital discharge: a follow-up study.

OBJECTIVE: The primary objective of this study was to confirm the results of a previous study that demonstrated a strong independent correlation between the severity of protein-energy undernutrition and the risk of 1-year postdischarge mortality in a population of older rehabilitation patients. DESIGN: Prospective survey (cohort study). SETTING: The Geriatric Rehabilitation Unit (GRU) of a Veterans Administration hospital. PARTICIPANTS: Of 350 randomly selected admissions to the GRU, 322 were discharged alive from the hospital. These 322 patients represented the study population, of whom 99% were male, and 75% were white. The average age of the study patients was 76 years. MEASUREMENTS: At admission and again at discharge, each patient completed a comprehensive medical, functional, neuropsychological, socioeconomic, and nutritional assessment. After discharge, each subject was tracked for 1 year. MAIN RESULTS: Within the 1-year posthospital discharge follow-up period, 64 study subjects (20%) died. This included 17% of the patients discharged home and 34% of the patients discharged to a nursing home (P < .01). Based on the Cox Proportional Hazards survival model, the variable most strongly associated with mortality was the discharge serum albumin, followed by discharge weight expressed as a percentage of ideal, self-dressing ability, and a discharge diagnosis of cardiac arrhythmia (usually atrial fibrillation). When all four of these variables were included in the analysis, the model was able to differentiate the survivors from those who died by years end with a sensitivity of 69%, a specificity of 69%, and an overall predictive accuracy of 69%. When tested using the data from the previous study, the model differentiated the patients who died from those who had not at a sensitivity of 62%, a specificity of 68%, and an overall predictive accuracy of 64%. CONCLUSIONS: Protein-energy undernutrition appears to be a strong independent risk factor for 1-year postdischarge mortality.

The Interrelationships among albumin, nutrient intake, and inflammation in elderly recuperative care patients.

OBJECTIVES: To examine the interrelationships among low serum albumin, nutritional depletion, and ongoing inflammation in older patients recovering from illness. DESIGN: A prospective cohort study. SETTING: A transitional care unit (TCU) within a Department of Veterans Affairs hospital nursing home care unit. PARTICIPANTS: 275 older veterans (mean age=78.9 ± 7.5y, 99% male) admitted for recuperative care and rehabilitation. MEASUREMENTS: At admission and discharge (median LOS 24d, IQR 16 to 44d), each subject completed a comprehensive standardized evaluation including a nutritional assessment and measurement of serum albumin, C-reactive protein (CRP), interleukin-6 (IL-6) and its soluble receptor, and tumor necrosis factor-alpha (TNF-α) and its soluble receptors (sTNF-RI and II). Complete nutrient intake assessments (calorie counts) were performed daily. RESULTS: Both the discharge albumin and the change in albumin (discharge minus admission) were strongly and inversely correlated with various indicators of inflammation, particularly CRP and IL-6. Change in CRP was the strongest correlate of change in albumin (R2 = 0.21, P<.001) and discharge IL-6 the strongest correlate of discharge albumin (R2 = 0.21, P<.001). Nutrient intake also correlated with albumin and its change, but entered the multivariable models after inflammatory indicators and explained a smaller portion of the variance. Although there were significant interactions between time and both nutrient intake and inflammation, the relative importance of inflammation as a potential determinant of the serum albumin concentration appeared to remain unchanged with longer periods of observation. CONCLUSIONS: Among elderly patients admitted to a TCU, inflammation appears to be a more powerful determinant of albumin and its change during the hospitalization than is nutrient intake. Further study is needed to prove causality and to determine whether the relative importance of inflammation on the albumin concentration diminishes with more prolonged periods of observation.

Nightly enteral nutrition support of elderly hip fracture patients: a phase I trial.

OBJECTIVE: This non-blinded randomized controlled trial was the first phase of a planned series of investigations designed to test the efficacy of aggressive post-operative enteral nutrition support to decrease the rate of post-operative complications or improve long-term outcomes in specifically defined subgroups of elderly patients who have sustained a hip fracture requiring surgery. METHODS: Eighteen patients (17 males) were randomized to the treatment (eight male subjects) or control groups. The control group (mean age 76.5+/-6.1 years) received standard post-operative care. Subjects in the treatment group (mean age 74.5+/-2.1 years) received 125 cc/hour of nasoenteral tube feedings over 11 hours each night in addition to standard post-operative nutritional care. RESULTS: Both the treatment and control groups had reduced volitional nutrient intakes for the first 7 post-operative days (3,966+/-2,238 vs. 4,263+/-2,916 kJ/day [948+/-535 vs. 1019+/-697 kcal/day], p=0.815), but the treatment subjects had a greater total nutrient intake (7,719+/-2,109 vs. 4,301+/-2,858 kJ/day [1845+/-504 vs. 1028+/-683 kcal], p=0.012). On average, treatment subjects were tube fed for 15.8+/-16.4 days. There was no difference between the groups (treatment vs. controls) in the rate of post-operative life-threatening complications (25 vs. 30%, p=1.00) or in-hospital mortality (0 vs. 30%, p=0.216). Mortality within 6 months subsequent to surgery was lower in the treatment group compared to the controls (0 vs. 50%, p=0.036). DISCUSSION: We conclude that nightly enteral feedings are a safe and effective means of supplementing nutrient intake. The greatest impact of nutrition support may be to reduce mortality.

Progressive resistance muscle strength training of hospitalized frail elderly.

OBJECTIVE: To determine whether frail elderly patients recuperating from acute illnesses could safely participate in and gain appreciable improvement in muscle strength from progressive resistance muscle strength training. DESIGN: Muscle strength (one repetition maximum), functional abilities (sit-to-stand maneuver and 20-sec maximal safe gait speed), and body composition were measured before and at the conclusion of a 10-wk program of lower limb progressive resistance muscle strength training. The nonrandomized study was conducted in a 30-bed geriatric rehabilitation unit of a university-affiliated Veterans Affairs hospital and a 28-bed transitional care unit of a community nursing home. Participants included 19 recuperating elderly subjects (14 male, 5 female; 13 ambulatory, 6 nonambulatory) >64 yr (mean age, 82.8+/-7.9 yr). RESULTS: The one repetition maximum increased an average of 74%+/-49% (median, 70%; interquartile range, 38%-95%, and an average of 20+/-13 kg (P = 0.0001). Sit-to-stand maneuver times improved in 15 of 19 cases (79%). Maximum safe gait speeds improved in 10 of 19 cases (53%). Four of the six nonambulatory subjects progressed to ambulatory status. No subject experienced a complication. CONCLUSIONS: A carefully monitored program of progressive resistance muscle strength training to regain muscle strength is a safe and possibly effective method for frail elderly recuperating from acute illnesses. A randomized control study is needed to examine the degree to which progressive resistance muscle strength training offers advantages, if any, over routine posthospital care that includes traditional low-intensity physical therapy.