Biomedical subjects
Publications and source records attributed to D Rudman.
The occurrence of renal insufficiency tends to increase in late adulthood. This common complication of old age is associated with increased physical dependency, morbidity, and mortality, and a lowered quality of life. In this review, the authors will develop the thesis that dietary practices during early and middle adulthood importantly influence the risk of renal insufficiency in the elderly.
We measured by photon absorptiometry the bone density at six sites in 65 nursing home men aged 57-85 y and in 25 independent community men aged 57-80 y. Average bone density in the community men ranged from 97% to 105% of age-matched normal men. In the nursing home men these values ranged from 71% to 92% of age-matched normal men (p less than 0.05 for comparison with the community men). About 50% of the nursing home men but none of the community men had a value less than 70% of age-matched normal men at one or more sites. Among the institutionalized men bone densities at all six sites (in g/cm2) were significantly (p less than 0.05) and directly correlated with body weight but were not significantly correlated with height, age, principal or secondary diagnoses, continuing medications, or functional level.
The effects on three nutrition-sensitive plasma proteins of isocaloric feedings with three enteral formulas were compared in 10 tube-fed male nursing home residents. The enteral products were Isocal (based on whole protein), Peptamen (based on a mixture of oligopeptides), and Vivonex T.E.N. (based on free amino acids). The nutrition-sensitive plasma proteins were albumin, transferrin, and retinol-binding protein. After observation during four weeks of feeding with Isocal, each subject was then monitored during four weeks of Peptamen and four weeks of Vivonex T.E.N. The latter two products were alternated in a crossover design. The shift of Isocal to Peptamen did not significantly (P greater than .05) influence the serum level of albumin, transferrin, or retinol-binding protein. In contrast, the shift of Isocal to Vivonex T.E.N. or of Peptamen to Vivonex caused a significant (P less than .05) decline in all three plasma proteins, the kinetics of their reductions corresponding to their known half-lives. The behavior of the three nutrition-sensitive plasma proteins suggests that in elderly nursing home men without gastrointestinal disease the nutritional value of the protein component of the three formulas follows the order Isocal = Peptamen greater than Vivonex T.E.N. However, this conclusion will require confirmation by nitrogen balance studies.
Previous studies have shown the normal range of plasma dehydroepiandrosterone sulfate (DHEAS) for independent community men over 60 years old to be 30-200 micrograms/dL. In human adults, low levels of plasma DHEAS have been correlated with a high mortality rate. In rodents, dehydroepiandrosterone, the precursor of DHEAS, has exhibited antidiabetic, anticarcinogenic, neurotropic, and memory-enhancing effects. We have now measured plasma DHEAS in 50 independent community men age 55-94 and in 61 nursing home men age 57-104. Mean DHEAS was significantly lower in the nursing home men than in the community men. Plasma DHEAS was subnormal (less than 30 micrograms/dL) in 40% of the nursing home residents and in only 6% of the community subjects. In both groups, DHEAS was inversely related to age. In the nursing home men, additionally, plasma DHEAS was inversely related to the presence of an organic brain syndrome and to the degree of dependence in activities of daily living. Plasma DHEAS was subnormal in 80% of the nursing home men who required total care. There was no significant correlation between the plasma concentrations of DHEAS and testosterone, or between plasma DHEAS and one-year mortality rate.
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One hundred fifty-three men, age 48-96, 86% white, had resided in this Nursing Home for an average of 6.3 years (range 1.3-36) as of August 1984. At that time, we reviewed their medical charts to record the numbers and sites of fractures which had been diagnosed during the preceding 1 to 5 years of Nursing Home residence, the duration of this period depending on the duration of institutionalization. In addition, a clinical database was compiled comprising 70 attributes, including diagnoses, drugs, plasma (serum) chemistries, and measures of hematologic, nutritional, and functional status. Fractures during the studied period of Nursing Home residence had occurred in 24 of 153 men; six residents had experienced two or more fractures. Fracture rates in hip, spine, and wrist were 2564, 366, and 549 per 100,000 patient years, respectively. The total fracture rate, hip fracture rate, and limb fracture rate were five to 11 times higher than in the age-matched general population of white men in the United States; in Rochester, MN; in Dundee, England; in Oxford, England; or in Finland. Univariate statistical analysis showed that the rates for hip fracture or for fracture at any site were significantly associated with 13 attributes: directly with age, plasma somatomedin C, blood urea N, serum creatinine, serum uric acid, serum 25-hydroxyvitamin D (25-OH-D), degree of functional impairment, and chronic urinary tract infection, and inversely with serum 1,25-dihydroxyvitamin D [1,25-(OH)2-D], serum albumin, hematocrit, and hemoglobin. There was not a significant correlation with the number of falls/month which occurred during the 7 months after August 1984. After the effect of age was partialed out, somatomedin C, 25-OH-D, 1,25-(OH)2-D, and the diagnosis of urinary tract infection were still significantly related to the occurrence of fractures. The fact that Nursing Home fracture cases had significantly higher blood urea nitrogen and 25-OH-D, and significantly lower 1,25-(OH)2-D, than their non-fracture counterparts suggests that impaired renal production of the latter vitamin D metabolite contributed to the excessive rate of fractures.
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The fasting amino acid profile in 22 healthy young men aged 25-35 y (group A) was compared with the fasting profile in 21 healthy independent men aged 65-85 y (group B), in 23 orally-fed nursing home men with dementia aged 65-92 y (group C), and in 17 tube-fed nursing home men with dementia aged 65-88 y (group D). Groups B, C, and D had significantly (p less than 0.05) lower levels of methionine and branched-chain amino acids than group A. Methionine was significantly lower in groups C and D than in group B. The ratio of essential to nonessential amino acids was significantly lower in groups B, C, and D than in group A. The data suggest that the intake of essential amino acids may often be suboptimal in both independent and institutionalized elderly men.
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Biosynthesis of cysteine from methionine via the hepatic transsulfuration pathway is impaired in some cirrhotic patients, who therefore might require cysteine in the diet. However, because further metabolism of cysteine also occurs primarily in the liver, the metabolic clearance of this amino acid could be impaired in cirrhosis. We administered oral loads of L-cysteine to cirrhotic patients and healthy volunteers. Plasma cyst(e)ine (free and protein-bound cysteine, and 1/2 cystine) and urinary sulfur-containing constituents were measured at various times postload. Cirrhotic subjects exhibited a greater maximal plasma cyst(e)ine concentration and plasma elimination half-life (t1/2) and a delayed excretion of metabolic end products after an oral L-cysteine load. The postload increase in total plasma cyst(e)ine was accounted for primarily by an increase in the disulfide form (cystine). These studies show that cirrhotics have an impaired ability to clear cyst(e)ine from the plasma.
We have analyzed the history of institutional fractures in 153 men, age 48 to 96, 86% white, who had resided in this VA nursing home for an average of 6.3 years as of August 1984. At that time, we reviewed their medical charts to record the numbers and sites of fractures which had been diagnosed during the preceding 1 to 5 years of nursing home residence, the duration of this period depending on the duration of institutionalization. Fractures during the period of nursing home residence under review had occurred in 24 of the 153 men; 6 residents had experienced two or more fractures. Fracture rates during institutionalization in hip, spine, and wrist were 2,564, 366, and 549/100,000 patient years, respectively. The incidence at all sites was 5,861/100,000 patient years. These rates were 5 to 11 times higher than the figures previously reported in the age-matched general population of white men in the United States, England, or Finland. The nursing home men who had experienced fractures at any site were significantly (nondirectional P less than 0.02) older than those who had not experienced any fracture. The hip fracture group, however, did not differ significantly (P greater than 0.05) in age from the no fracture group.
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Severely dependent tube-fed elderly men with dementia in this VA nursing home are nourished exclusively with Isocal, which provides only four fatty acids in amounts over 1% of the total (palmitic, oleic, linoleic, and alpha-linolenic). It has not been proven that the frail elderly can efficiently convert linoleic to arachidonic acid, and alpha-linolenic to eicosapentanoic and docosahexaenoic acids. Therefore, we compared the serum profile of fatty acids in six of the tube-fed elderly men with the profile of six healthy young men eating mixed foods ad lib. Expressed as percent of total fatty acids, arachidonic, eicosapentanoic and docosahexaenoic acids did not differ significantly between the two groups. The data show that linoleic and alpha-linolenic acids satisfy the requirements for omega 6 and omega 3 fatty acids, respectively, in severely impaired elderly men.
Plasma testosterone (T) was measured at 8-9 a.m. in 44 men chronically institutionalized in a Veterans Administration Nursing Home, and correlated with an extensive clinical data base (including age, diagnoses, drugs, laboratory tests, anthropometric measurements, and mortality during the year after the T analysis). Age averaged 76.4 years (range 60-95). Plasma T was below the lower limit of the normal range for healthy young men (i.e. less than 300 ng/dl) in 46% of the men studied. Samples containing low T (less than 300 ng/dl) also contained subnormal unbound T, but normal concentrations of thyroxine and cortisol. Of the low T samples, 45% contained elevated LH, FSH or both (over 20 mU/ml), and the remaining 55% contained LH and FSH levels below this threshold, these two subgroups representing peripheral and central hypogonadism respectively. Plasma T was significantly (p less than 0.02) correlated in a direct relationship with hemoglobin, serum cholesterol, and the occurrence of seizures.
This study examined the descriptive epidemiology of seizure disorder in 129 male residents of a Veterans Administration Nursing Home. Eighty-seven of the residents were institutionalized because of nonpsychiatric disorders (60 for chronic neurologic diseases, and 27 for other medical conditions). Forty-two were institutionalized because of a chronic psychosis (39 for schizophrenia, three for affective disorders). We determined for each resident an extensive clinical data base of 54 items including measures of hematologic, nutritional, metabolic and endocrine status, as well as continuing medications. In the nonpsychiatric group, 16 of the 87 men had a seizure disorder. In the psychiatric group, this proportion was only three of 42. The prevalence of epilepsy in the nonpsychiatric group was 20-40 times greater than in the aged-matched general population of men. In the nonpsychiatric group, the onset of seizures followed the onset of organic brain disease. Forty-five percent of seizure disorders occurred in men who had experienced a cerebrovascular accident, and 23% in men with other types of chronic brain disease. The seizures of the nonpsychiatric men had been observed to be generalized clonic-tonic in 45%, and partial complex in 22%. Ninety-four percent of the nonpsychiatric men with epilepsy received anticonvulsants, and none had experienced more than one seizure during the preceding year. Univariate statistical analysis of the 54 item data base showed that the occurrence of seizure disorder correlated inversely with age, blood urea nitrogen, serum creatinine and serum bilirubin, and directly with plasma testosterone, hemoglobin, use of anticonvulsants, and use of psychotherapeutic agents.(ABSTRACT TRUNCATED AT 250 WORDS)
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Little is known about bacteremia in long-term care facilities. We have conducted a retrospective study during a 12-month period analyzing the clinical correlates of bacteremia in 533 chronically institutionalized, predominantly male patients, with an average age of 69 years. Thirty-four men had forty-two bacteremic illnesses during this period. The incidence rate was 0.30 episodes per 1000 patient care days, and the mortality rate was 21%. The urinary tract was the most frequently identified tissue source (56%), followed by respiratory tract (7%) and skin (7%). Providencia stuartii was the most common gram-negative organism, while Staphylococcus aureus, Streptococcus pneumoniae and enterococcus were the frequent gram-positive microbes. Gram-negative bacteremia accounted for 63% of the episodes (15% mortality rate), and gram-positive bacteremia accounted for 27% (18% mortality rate); 10% of the bacteremias were polymicrobial (25% mortality rate). Most of the isolated organisms were sensitive to available antimicrobial agents. The leading risk factor for bacteremia was an indwelling urinary catheter (odds ratio 39, 95% confidence limits 16 to 97). Patients with urinary catheters at the beginning of the study constituted only 5% of the population, but accounted for 40% of the gram-negative bacteremias during the year of observation.
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