Obesity Paradox in Caucasian Seniors: Results of the PolSenior Study.

OBJECTIVES: To investigate the influence of overweight and obesity on general performance and mortality in seniors. DESIGN: Cross-sectional multidisciplinary study on ageing of the Polish population. SETTING: Community-dwelling individuals aged 65 years or older, selected using three-stage stratified, proportional draw. PARTICIPANTS: 4944 Polish Caucasian seniors, aged 65 years or older recruited between October 2007 and October 2010. MEASUREMENTS: All study subjects underwent measurement of body mass index (BMI), waist circumference (WC), and arm circumference (AC). The physical and cognitive performance was evaluated using the Katz Activities of Daily Living (ADL) score and Mini-Mental State Examination (MMSE), respectively. Morbidity data were obtained from a medical questionnaire. Mortality data were obtained from the Population Register of Poland between October 2015 and October 2018. RESULTS: Increasing age was associated with a decreased prevalence of obesity (all p<0.001). Higher BMI, WC and AC values were associated with higher ADL and MMSE scores (all p<0.001). On multivariate analysis, all three body measurements in women remained independent predictors of the ADL score (BMI p=0.002, WC p=0.005, AC p<0.001) and MMSE score (p<0.001, p=0.003, p<0.001). In men, physical functioning was associated with AC (p=0.003), and cognitive status was associated with AC (p<0.001) and BMI (p=0.013). There was no association between general obesity, abdominal obesity, or AC with several aging-related adverse conditions. Kaplan-Meier survival curves showed that overweight and obesity were associated with the lowest mortality. On multivariate analysis, BMI and AC values remained independent predictors of mortality. In successfully aging individuals, neither BMI, WC, nor AC remained such predictors. CONCLUSIONS: Overweight and obesity in Caucasian seniors are not associated with deterioration of physical and cognitive function or with increased mortality.

The impact of the age range of young healthy reference population on the cut-off points for low muscle mass necessary for the diagnosis of sarcopenia.

OBJECTIVE: According to the consensus report published by the European Working Group on Sarcopenia in Older People (EWGSOP), sarcopenia researchers should determine sex-specific cut-off points (COPs) for low muscle mass (LMM) in their respective countries. To this end, it is necessary to investigate young healthy adults' group (YHAG). As the EWGSOP hasn't specified any inclusion criteria for this group, there is a significant divergence in literature regarding the age range characterizing YHAG. Therefore, the primary aim of our study was to assess the impact of different YHAG age ranges on the calculated values of COPs for LMM. The secondary aims were to use the calculated COPs for evaluating the prevalence of sarcopenia among the older people from Poland. MATERIALS AND METHODS: 1512 young healthy individuals were divided into six age subgroups: 20-30, 18-40, 18-39, 20-39, 20-40, and 20-35 years. The sex-specific COPs for LMM were calculated using the Appendicular Lean Mass index. The prevalence of sarcopenia was assessed in 468 older adults from Poland. RESULTS: In the six age subgroups, six different COPs were obtained in the group of young women (ranging from 5.51 kg/m2 to 5.60 kg/m2), and three different COPs were found in the group of young men (ranging from 7.35 kg/m2 to 7.40 kg/m2). After applying the determined COPs, the overall prevalence of sarcopenia was found to range between 4.5% and 5.1%. CONCLUSIONS: Since there are no guidelines establishing the YHAG age range, if multiple sex-specific COPs are obtained, the highest values should be applied in the diagnostic of sarcopenia to avoid the misclassification of patients with this disease.

Prevalence of anemia in relation to socio-economic factors in elderly Polish population: the results of PolSenior study.

Anemia is an independent risk factor for functional decline and mortality among older adults. Since mild anemia in older people is often under-diagnosed and ignored, its prevalence needs precise determination and recognition of predisposing factors. None of the previous studies based on the data obtained from the representative elderly population identified the influence of socio-economic factors on the prevalence of anemia. PolSenior was a cross-sectional population-based study performed on the nationally representative sample of Polish seniors. Complete blood count was assessed in 4003 respondents aged 65 years or above (1910 women) divided into six five-year cohorts and a reference group of 622 people aged 55 - 59 years (333 women). Anemia was defined based on the WHO criteria: Hb < 12.0 g/dL in women and Hb < 13.0 g/dL in men. The following socio-economic factors were evaluated through the multiple logistic regression analysis: education level, marital status, place of residence, living arrangements and self-reported poverty. The prevalence of anemia in older persons standardized for the population was 10.8% (17.4% of the study group) and was more frequent in men than in women (20.8% versus 13.6%). The frequency of anemia progressed with age from 5.3% in the youngest to 37.7% in the oldest cohort, and the progression was higher in men. The multiple logistic regression analysis revealed the link between anemia and age in both genders, as well as unmarried status and urban dwelling in men. When age was not taken into account, logistic regression showed the link between anemia and unmarried status, urban place of residence (both genders), and low level of education (women only). Among seniors, those poorly educated, unmarried and city inhabitants require intense screening for anemia.

The most common factors hindering the independent functioning of the elderly at home by age and sex.

OBJECTIVE: Changes occurring with increased age as well progressive illnesses can negatively affect the independent functioning of older people. The goal of this study was to identify the most common problems that make independent life at home more difficult for the elderly and to try and present their relation with age and gender. PATIENTS AND METHODS: A total of 506 persons over 60 years of age took part in the study. They were residents of Poznan, Poland and surrounding areas. The research instruments were the Abbreviated Mental Test Score and EASY-Care Standard 2010 questionnaire which makes it possible to analyze patient's functioning in seven areas and includes three risk scales: Independence score, Risk of breakdown in care, Risk of falls. RESULTS: In the group studied the greatest difficulties included performing complex activities of everyday life connected with moving around (III area), difficulties with performing household tasks (50.8%), shopping (39.7%) and falls (35.0%). The most frequently reported symptom that was a cause of worry was pain (68.2%). Other health problems reported included sleep disorders (58.9%), incorrect body weight (52.6%), low tolerance of physical effort (48.4%), urethral sphincter functioning disorder (42.7%) and forgetfulness (40.5%). The feeling of being lonely was found in 45.8% of older people. CONCLUSIONS: Significant differences in functioning between the genders were found in the areas of meal preparation, falls, mobility outside the home, not feeling safe, lack of physical activity, low tolerance of physical effort and almost all of area VII - Mental health and well-being. The main determinants of risk scores with the Independence Score, Risk of breakdown in care and Risk of fall domains were age and subjective feelings of pain.

Health status correlates of malnutrition in the polish elderly population - Results of the Polsenior Study.

OBJECTIVE: The aim of the study was to analyze health-related factors associated with poor nutritional status (PNS) of a representative group of Polish older people, based on data from the PolSenior project (the first nation-wide study of Polish senior citizens). PATIENTS AND METHODS: Nutritional status was assessed in 3751 community-dwelling older people (1770 females, mean age: 77.4±8.0 years) using the Mini Nutritional Assessment - Short Form. Elements of comprehensive geriatric assessment (cognitive and mood screening), selected medical data were analyzed in relation to the nutritional status. These were: the number of medications, the number of chronic diseases, selected diseases potentially related to malnutrition (anaemia, stroke, peptic ulcer, Parkinson's disease, cancer - past or present), total edentulism, use of dentures, and chronic pain. RESULTS: PNS was observed in 44.2% of participants. Female sex [OR 1.72, 95% Cl (1.45-2.04)], advanced age [OR 2.16 (1.80-2.58)], symptoms of depression [OR 11.52 (9.24-14.38)], cognitive impairment [OR 1.52 (1.20-1.93], multimorbidity [OR 1.27 (1.04-1.57)], anaemia [OR 1.80 (1.41-2.29)] and total edentulism [OR 1.26 (1.06-1.49)] were independently correlated with PNS. CONCLUSIONS: PNS in Polish elderly population is strongly related to the occurrence of symptoms of depression. People in advanced age with symptoms of depression, cognitive impairment, multimorbidity, anaemia and total edentulism should be screened and monitored for early symptoms of malnutrition.

Factors contributing to cognitive deficits in elderly residents of rural areas.

OBJECTIVE: Due to the growing aging of societies an increasingly large group of people suffers from age-related impairment of cognitive functions and thus reducing the quality of life of the elderly. The purpose of the study was to evaluate the efficiency of cognitive functions in a group of aging residents of rural areas. PATIENTS AND METHODS: The inhabitants of a rural area were recruited and assessed: cognitive function as well as intellectual and physical activity, number of years of education, presence of diseases, using stimulants, diet, sources of living, marital status and family situation Subjects were divided into two groups: persons above 65 and older, constituting the studied group and persons between 40 and 64 years of age, constituting the control group. Both groups did not significantly differ in terms of sex or years of education. RESULTS: Statistically significant differences (p < 0.05) were found in the results of the tests concerning such functions as the sight recognition memory and spatial recognition memory, spatial operating memory both on the strategy level and on the level of committed errors. An analysis of the results obtained in the group of elderly people did not indicate any major differences between men and women as regards the analyzed cognitive functions, no statistically significant differences were found in cognitive testing depending on the number of years of education. The studied persons included in the physically active group scored better in the visual memory and learning tests. CONCLUSIONS: The conducted studies elucidated the dependence of the level of cognitive functions on age, a positive impact of physical activity on some cognitive functions, however we could not find differences between the efficiency of those functions and education, sex, presence of somatic diseases and activity of persons aged > 65.

Social and economic correlates of malnutrition in Polish elderly population: the results of PolSenior study.

OBJECTIVES: The aim of this study was to evaluate the prevalence of malnutrition in Polish elderly population and analyse its social and economic correlates based on the data from the PolSenior project, the first large-scale study of a representative group of Polish seniors. DESIGN: A cross-sectional population-based study. SETTING: All territorial provinces in Poland. PARTICIPANTS: 4482 community-dwelling respondents aged 65 years or above (women: n=2142, age=79.0±8.4 years; men: n=2340, age= 78.3±8.6 years). MEASUREMENTS: The nutritional status of participants was assessed through the Mini Nutritional Assessment Short Form (the revised MNA-SF). Out of social and economic correlates we evaluated age, sex, level of education, marital status, place of residence, living conditions and economic status. Economic status of the respondents was determined on the basis of questions on how well they could manage their own budgets. Those who could afford only the cheapest food or clothes were considered the group of self-reported poverty. RESULTS: Frequency of malnutrition in the PolSenior population accounted for 7.5% (in 5.0% men and 9.0% women; p<0.001). The risk of malnutrition was present in 38.9% (33.3% men and 42.4% women; p<0.001). In our study female sex, older age, unmarried status, living in a rural area and self-reported poverty were independent correlates of malnutrition. CONCLUSIONS: Our data showed high prevalence of malnutrition and the risk of its development among the community-dwelling elderly people in Poland. Screening with MNA-SF should focus in particular on unmarried, poorly educated individuals, in late old age, living in rural areas and self-reporting a poor financial state, especially women.

Association of cognitive performance with the physical activity and body mass index in middle-aged and older rural inhabitants.

OBJECTIVE: Last few decades have witnessed rapid ageing of the population. The prevalence of mild cognitive impairment and dementia is significantly higher in people aged 60 and over than in younger. The aim of the study was the assessment of the putative associations between physical activity and cognitive functioning in elderly inhabitants of a rural area. PATIENTS AND METHODS: The participants underwent physical assessment, physical activity, cognitive functions, depression were assessed. RESULTS: Highly active participants had better results in tests assessing psychomotor speed and in measuring attention and its flexibility comparing to groups of medium and low physical activity. Active people made fewer errors in the test measuring visual memory and new learning, and had significantly better results in the spatial-recognition memory test. Persons with symptoms of depression performed worse in visuospatial memory and working memory tests. Associations between physical activity and cognitive test results as well as association between body mass index and blood pressure and cognitive performance were observed. CONCLUSIONS: The results of the study suggest an association between higher physical activity and better cognitive functioning in the field of working memory and visual and spatial-recognition, attention and attention flexibility. Symptoms of depression, hypertension and increased BMI may adversely affect cognitive performance in elderly.

Obesity itself does not influence BDNF serum levels in adults.

OBJECTIVE: In European countries more than 50% of the population are overweight, 30% with obesity. In Poland overweight was present in 41% of men and 28.7% of women (obesity 15.7% and 19.9%). It was examined whether obesity affects serum levels of brain-derived neurotrophic factor (BDNF) and interleukin-6 (IL-6), which may lead to the consequences of obesity, such as type 2 diabetes, hypertension, and finally the metabolic syndrome. We aimed to examine whether obesity affects the serum levels of BDNF and IL-6. PATIENTS AND METHODS: The study involved 144 people aged 45 to 86 years, 80 subjects with diagnosed obesity and 64 with normal body weight, ≤ 65 years old (n = 45) and > 65 years old (n = 99). All patients underwent tests of glucose, total cholesterol, HDL, LDL, triglycerides levels, using routine laboratory methods. A test of the concentration of IL-6 and BDNF was carried out. The declared level of physical activity (gymnastics, cycling or walking) was considered. RESULTS: It was shown that in women ≤ 65 years old, obesity was associated with higher levels of interleukin-6. When the test group, divided into the above categories, was analyzed for the diagnosis of hypertension, heart failure or diabetes mellitus, no statistically significant differences in the investigated parameters were detected. The concentration of brain-derived neurotrophic factor did not differ in the investigated subjects, regardless of sex, age, obesity, or the declared physical activity. CONCLUSIONS: The concentration of interleukin-6 in younger people, including those with normal body weight, correlated with total cholesterol and triglyceride levels, and it was significantly higher in obese women compared to those with normal body weight.

Drug consumption among Polish centenarians.

The aim of the study was to describe the quantitative and qualitative aspects of pharmacotherapy of Polish centenarians. The studied group consisted of 92 centenarians (mean age: 101.7±1.2 years, 77 females, mean age: 101.5±1.2; 15 males mean age: 102.2±1.2). Among the studied subjects, 18 individuals (19.6% of all subjects) did not use any drugs in his or her daily regimen. The mean number of drugs per person was 2.5±2.5 drugs (prescription drugs: 1.9±2.2 and non-prescription drugs: 0.5±0.8). Fifty-six centenarians (60.9% of all studied subjects) took concomitantly 0-3 drugs daily while 36 (39.1%) took more than 3 drugs daily. Within this group, 30 centenarians (32.6%) took 5 or more drugs concomitantly every day. The most commonly used groups of drugs were: gastrointestinal drugs (55 centenarians, 74.3% of all drug consumed), cardiovascular drugs (51 centenarians, 68.9%) and central nervous system drugs (N) (38 centenarians, 51.4%). In the studied group, 6 persons (8.1% of all drug consumers) were taking one potentially inappropriate drug based on the Beers criteria. To conclude, the mean number of drugs, the prevalence of polypharmacy, and the tendency for potential inappropriateness of treatment are lower among Polish centenarians comparing to the common elderly.

The effect on renal structure and function of late-life-introduced caloric restriction (CR) in rats.

Previous studies have shown that life-long caloric restriction in rats protects the kidneys from age-dependent injury. In this study, we analyzed whether late-life-introduced caloric restriction has a similar effect. The study lasted 12 months. Three groups of animals were analyzed: rats fed "ad libitum" (AD, n = 9), rats on 60% caloric restriction (CR, n = 9), and rats fed "ad libitum" for the first six months of their life then switched to 60% caloric restriction thereafter (LCR, n = 9). At the end of the study kidney function was assessed and kidney samples were analyzed histologically. Serum creatinine and urine albumin were higher in AD than in both CR and LCR (P < 0.001). Creatinine clearance (Cl(cr)) corrected for body weight was lowest in AD and comparable in CR and LCR. Similarly Cl(cr) corrected for kidney weight was lower in AD than in both CR and LCR (P < 0.05). Severe albuminuria was observed only in AD. In CR and LCR the amount of albumin excreted was comparable (AD vs. CR, P < 0.0001; AD vs. LCR, P < 0.001). In morphometric analysis, the mean size of the glomeruli was higher in AD than in both CR and LCR (P < 0.01). Similar results were found for the mesangial area (AD vs. CR, P < 0.001; AD vs. LCR, P < 0.01) and for mesangial cell counts (AD vs. CR, P < 0.001; AD vs. LCR, P < 0.05). No difference was found between CR and LCR in morphometry. In conclusion, our study indicates that late-life introduction of caloric restriction reverses most of the structural and functional changes observed in the kidneys of "ad libitum"-fed rats.

Polypharmacy and potential inappropriateness of pharmaco-logical treatment among community-dwelling elderly patients.

In this study, we describe the phenomenon of polypharmacy and the frequency of the potential inappropriate medication use, according to the criteria of Beers (Beers, M.H. (1997): Explicit criteria for determining potentially inappropriate medication use by the elderly. An update. Arch. Intern. Med. 157. 1531-153 C) among elderly subjects in Poland. The study involved 680 individuals (including 438 women and 242 men) aged 65 years and more (mean age: 72.6+/-6.5 years) residing in Poznan (P) and 320 (216 women and 104 men (mean age: 72.5+/-6.0 years) residing in Glogow (G). The average number of all drugs taken by the analyzed patients was more than 6 (P: 6.9+/-3.2, range: 0-17 drugs, and in G: 6.6+/-3.1, 0-16), of prescribed drugs, more than 5 (P: 5.3+/-2.8, range: 0-15 drugs, G: 5.2+/-2.8, ranging 0-16) and of non-prescribed drugs, more than 1 (P: 1.6+/-1.5, range: 0-11 drugs, G: 1.4+/-1.4, range 0-8). As far as the frequency of the potential inappropriate medication use is concerned, almost one third of all persons, (285 persons, 28.2% of all), in P: 195 persons (28.6% of the subjects), in G: 90 (27.2%) used at least one of the potential inappropriate medications. Polypharmacy and the potential inappropriateness of pharmacological treatment are common in community-dwelling elderly subjects in Poland. There is a great need to improve the quality of medication use in this group of patients. In order to do it we have elaborated and nowadays we introduce the project of pharmaceutical care in Poland.

Duplicate use of angiotesin-converting enzyme (ACE) inhibitors in a community-dwelling elderly population in Poland.

In this paper the data on the duplicate use of ACE inhibitors among a community-dwelling elderly population are presented. Using a questionnaire, 1000 subjects were interviewed concerning the use of drugs, 654 females, mean+/-SD age: 72.6+/-6.5 years. They were divided into two groups: Group A (5%) taking at least two ACE inhibitors (n=50) and Group B: those who used either a single ACE inhibitor or no ACE inhibitor (n=950). In Group A, 49 individuals were taking two different ACE inhibitors concomitantly and one was using three. The most commonly used ACE inhibitor was enalapril (29 of 50 subjects). Subjects in Group A consumed significantly more drugs, both of prescription (Rx) and nonprescription (OTC), compared to those in Group B (total means: 8.4+/-2.8 vs. 6.7+/-3.2; p<0.01, Rx means: 6.3+/-2.5 vs. 5.2+/-2.8, p<0.05, OTC means: 2.0+/-1.6 vs. 1.6+/-1.5, p<0.05). Also, they were more likely to have consulted a cardiologist (17/50 vs. 201/950, p<0.05). The duplicate use of ACE inhibitors in 5% of a population of community-dwelling elderly patients seems to be caused by both poor doctor-doctor communication and polypharmacy. This phenomenon could possibly be dangerous especially when potential additive adverse effects are taken into account.

Difference in estimated GFR with two different formulas in elderly individuals.

The aim of this study was to characterize the differences between the prediction of GFR with Cockcroft-Gault formula (CG=(140-age)/(72 x PCr (mg/ml), for females multiplied by 0.85) and the new formula based on the multicenter trial of the Modification of Diet in Renal Diseases (MDRD=186 x P (Cr) (-1.154) x age(-0.203); 0.742 if patient is female) in elderly subjects. The study involved 100 individuals aged 65-111 years (mean age 88.3+/-14.7; 79 females and 21 males). In all subjects GFR was estimated according to both formulas mentioned above and expressed in ml/min/1.73 m2. Thereafter we calculated the difference between MDRD and CG (MDRD-CG) and analyzed its determinants in every subject. Mean GFR, obtained with MDRD was 76.0+/-24.0, whereas according to CG 67.9+/-18.6 (p < 0.0001). However, the mean MDRD-CG was up to 30.0+/-26.6 which means that MDRD results were much higher in comparison with CG. Using the multiple linear regression analysis we showed that MDRD-CG strongly depend on age (p < 0.0001), BMI (p < 0.0001) and serum creatinine concentration (p<0.0001). However, the gender has not effect on MDRD-CG value. The values of MDRD-CG strongly and positively correlated with age (r=0.7027, p < 0.0001) and negatively both with body mass index (r=-0.7171, p < 0.0001) and serum creatinine (r=-0.5590, p < 0.0001). In summary, our results show that the difference between MDRD and CG strongly depends on age, BMI and Scr. Investigators should be aware of these differences and take it into account in elderly.

Blood pressure in centenarians in Poland.

The objective of the study is assessment of the prevalence and type of hypertension in centenarians in Poland. The investigations included 92 people who had turned 100 years of age, who, within the protocol of the Project of Investigation Polish Centenarians, underwent genetic, anthropometric, psychological and sociological examinations, and whose cardiovascular system was assessed. In the present analysis, we are analysing data concerning their blood pressure (BP) assessed by several measurements (3-6) with the mercury sphygmomanometer on both arms in sitting (if possible) or lying position performed during one visit. Hypertension was diagnosed when average BP value exceeded > or = 160/95 or > or = 140/90 mmHg. The average of age was 101.2 years (range 100-111 years), the respective values for BP were: systolic 146.7 mmHg (99-213 mmHg), diastolic BP--80.3 mmHg (55-114 mmHg) and pulse pressure (PP) 66.4 mmHg (31-129 mmHg). Hypertension diagnosed based on the criterion > or = 160/95 mmHg was found in 29% of subjects, and according to the recent WHO criterion (> or = 140/90 mmHg) in 65% of subjects. PP exceeded 65 mmHg in 44.6%, and was above 50 mmHg in 91% subjects. In conclusion, hypertension occurs less frequently in centenarians, than in the entire population of old people, but it nevertheless cannot be considered a rare condition.

Kidney function estimated with different formulas in centenarians.

PURPOSE: There are growing doubts about the accuracy of Cockcroft-Gault formula (CG) used for the estimation of creatinine clearance, especially in elderly. Recently, the authors of the multicenter trial of the Modification of Diet in Renal Diseases (MDRD) have proposed a new equation. Moreover, Baracskay et al. (B), proposed the special formula for the estimation of kidney function (KF) in elderly. The aim of our study was to compare the results of KF calculated with these three formulas in centenarians. MATERIAL AND METHODS: The study involved 50 centenarian subjects aged 100-111 years (41 females and 9 males) who participated in Polish Centenarians Program. In all of them KF was estimated with the CG, B and MDRD formulas. RESULTS: In the whole population examined, the mean KF according to CG was lower in comparison to both others (p < 0.001 vs both B and MDRD). Also, in females CG results were the lowest (p < 0.001 vs both B and MDRD). In contrast, KF calculated according to CG and B did not differ in males. The results of the MDRD formula significantly exceeded the two others also in males (p < 0.001 vs CG and B). No impact of gender on the obtained results could be found when CG and MDRD were used. However, according to B, the mean values for females were higher (p < 0.01). CONCLUSIONS: KF calculated with the CG, B and MDRD formulas significantly differed in the centenarians examined. Thus, further studies, which include a reference standard, are necessary to answer the question which of these mathematical formulas is the most reliable for the calculation of KF in the elderly.

Pathophysiology of ageing.

Ageing is characterized by a gradual decline in organ functional reserves which reduces the ability to maintain homeostasis under conditions of stress. Introduction of cell culture and molecular biology techniques has provided new experimental tools for the analysis of ageing at the molecular level. During ageing progressive degeneration of cells and loss of regenerative capacity are enhanced and with time the alterations caused by them ultimately lead to death. In this paper the current knowledge of the mechanisms of ageing is summarized.

The ultrastructure of the peritoneal membrane in chronically dialysed rats with spontaneous peritonitis: preliminary observations.

In this paper we describe ultrastructure of the peritoneal membrane from single peritoneal biopsies collected from chronically dialysed rats with spontaneous peritonitis. The results were compared with those obtained in chronically dialysed animals without peritonitis. In rats with peritonitis, peritoneum was much thicker than in peritonitis-free animals. The increased thickness of the peritoneum during peritonitis was due to infiltration of the submesothelial tissue with oedematous fluid and to the presence of huge amount of cells in the stroma. The connective tissue cells were accumulated just underneath the peritoneal surface. In deeper parts of the interstitium, infiltrating acute inflammatory cells were present (lymphocytes, polymorphonuclear cells: neutrophils and eosinophils). Inversely, the increased thickness of the peritoneum in peritonitis-free animals was mainly due to enhanced amounts of collagen. Additionally, in rats with peritonitis, the surface was often denuded of mesothelial cells. The damaged mesothelial cells that detached from the peritoneal surface were also found. In conclusion, the morphological changes observed in rats with peritonitis are similar to those reported in humans, thus the model of peritonitis in dialysed rats can be used for the study of peritoneal remodeling during peritoneal dialysis complicated by peritonitis.

Plasma glutathione peroxidase activity in the elderly.

Schiavon et al. (1994) have reported that the measurement of plasma glutathione peroxidase activity (PGP) could provide an index of renal function. Its activity, which was depressed in patients with impaired renal function, correlated positively with creatinine clearance and negatively with serum creatinine. To evaluate the hypothesis that the plasma PGP activity may be used to assess renal function in elderly, we measured the plasma PGP and creatinine clearance (ClCr) in 65 active, community-dwelling elderly (range: 65-93 years; 47 women and 18 men). We did not include persons with advanced renal failure in our study. PGP did not correlate with PCr and it was similar among patients with normal and with increased PCr (127.0 +/- 30.7 U/l and 119.7 +/- 21.6 U/l, respectively). A positive correlation was found between PGP and ClCr (r = 0.30; p < 0.01). Plasma PGP activity was lower in patients with a ClCr lower than 70 ml/min/1.73 m2 than in those who had a higher ClCr (113.0 +/- 25.8 U/l and 131.2 +/- 26.7 U/l, p < 0.01). However, no correlation was found between ClCr and PGP in subjects with lower ClCr. PGP did not correlate with age but there was a correlation between ClCr and age (r = -0.24, p < 0.05). Our results suggest that plasma PGP activity is decreased in the patients with impaired renal function but this decrease does not correlate with age-dependent decline of kidney function.

A comparison of the biocompatibility of phosphate-buffered saline and dianeal 3.86% in the rat model of peritoneal dialysis.

Phosphate-buffered saline (PBS), an isotonic solution with a physiologic pH can be considered an example of a biocompatible dialysis fluid. This study compared the biocompatibility of PBS with that of Dianeal 3.86% (Baxter Healthcare Corporation, Deerfield, IL, U.S.A.), using a model of peritoneal dialysis in the rat. In an acute experiment, after catheter implantation, rats were infused on day 1 with PBS, on day 5 with standard dialysis solution (Dianeal 3.86%), and on day 7 again with PBS. When rats were injected with Dianeal 3.86%, the inflammatory reaction was suppressed as compared with PBS. The cell count was lower with Dianeal (-85%, p < 0.001), the neutrophil:macrophage ratio in dialysate was 80% lower (p < 0.01), total protein concentration in the Dianeal dialysate was 73% lower (p < 0.01), and the dialysate nitrite level was 45% lower (p < 0.01). In a chronic experiment, after catheter implantation, rats were dialyzed for four weeks with PBS or with Dianeal 3.86%. At the end of the study, a 1-hour peritoneal equilibration test (PET) was performed. As evaluated on a semiquantitative scale, macroscopic changes in the peritoneum were more severe in rats exposed to PBS than in those exposed to Dianeal 3.86% (8.6 +/- 3.2 vs 5.2 +/- 2.6, p < 0.05). The thickness of the visceral peritoneum was comparable in both groups; but, in PBS-treated rats, the peritoneal interstitium contained more inflammatory cells and more new vessels. During the 1-hour PET, peritoneal permeability to water and solutes was comparable in the two groups. Despite a more physiologic composition, PBS is a less biocompatible peritoneal dialysis solutions than is standard, acidic, hypertonic dialysis solution.