Circulating aminopeptidase activities in men and women with essential hypertension.

Essential hypertension is one of the major contributors to premature morbidity and mortality due to the incresased risk for coronary heart disease, stroke, renal disease, peripheral vascular disease and vascular dementia for both men and women. However, its basic causes remain unknown. In the present work we studied the activity of several proteolytic regulatory enzymes related to renin-angiotensin-system (RAS) (aminopeptidase A, APA; aminopeptidase N, APN; aminopeptidase B, APB; and insulin-regulated aminopeptidase, IRAP); with oxytocin regulation (oxytocinase); with the metabolism of GnRH and TRH (pyrrolidone carboxypeptidase, Pcp); and with enkephalins metabolism (enkephalindegrading activity, EDA), to elucidate their role in the mechanisms responsible of essential hypertension and to discuss the possible gender differences. Serum samples of 53 individuals with essential hypertension and 60 healthy volunteers were collected and used to assay enzyme activities, gonad hormones testosterone and estradiol, TSH and free thyroxin (fT4). Differences were observed in APA, APN, Pcp and EDA specific activities, and in serum gonad hormone levels between hypertensive and control groups. Only Pcp activity showed gender differences. Regarding the RAS, APA is reduced while APN is increased, suggesting increased levels of angiotensin II and a facilitation of the conversion of angiotensin III in angiotensin IV. Thus, the changes in several RAS-regulating specific activities and other enzyme activities involved in the neuroendocrine modulation of gonad and stress-related functions are related to essential hypertension with minor gender differences. Therefore, aminopeptidases constitute new elements for the knowledge of the causes of essential hypertension and an alternative as therapeutic targets against the illness.

How do disorders related to hospitalisation influence haemodialysis patients' nutrition?

INTRODUCTION: Hospitalizations are frequent in hemodialysis patients and is often accompanied by nutritional deterioration showed by a loss of weight and a reduction of albumin serum levels. This phenomenon is related with length of stay having its origin in a complex interplay of factors. Our aim in this study was to analyze if changes in body weight and other nutritional parameters are influenced by the illnesses presented during hospitalization. PATIENTS AND METHODS: Over a period of three years, we retrospectively chose chronic haemodialysis patients that were admitted for more than four days, excluding those cases that died in the hospital. We randomly chose one admission episode per patient so as to avoid excessive weighing of repeated admissions. We took data concerning weight changes, pre-admission and post-discharge analytical results, analytical results following first week of hospital stay, disorders causing hospital admission and those that developed during the hospital stay. We created a point score system to record the total of illnesses presented. RESULTS: The study included 77 patients, aged 67±12 years and having undergone haemodialysis for 31±34 months. Hospital stay was 17.8±12.6 days (median, 12 days). We observed that many patients admitted for digestive and osteoarticular disorders, heart failure or coronary syndrome lost more weight during their hospital stay, although no significant differences were reached. The total number of disorders suffered during the hospital stay was independent of the cause of hospitalisation. Anaemia,heart arrhythmias and signs of heart failure were associated with longer hospital stays, however it was only anaemia that was significantly related to greater weight loss. Weight loss was not related to surgery or infections. Albumin levels during the first week of hospital stay were different depending on the disorder upon admission. It was lower when the patients were admitted for digestive disorders (ANOVA, P=.05). Changes in albumin and creatinine levels before and after the hospital stay did not differ among disorders. We observed a relationship between having presented with more disorders during the stay and a longer stay, lower initial albumin and greater weight loss following discharge. In the multivariate analysis, we found the following weight loss predictors: stay, anaemia, and sepsis. We also found the following hospital stay predictors:Charlson's comorbidity index, heart arrhythmias, anaemia, sepsis and surgery. CONCLUSIONS: Malnutrition during the hospital stay depends on the duration and the number of disorders that develop during this time, the cause of admission having less impact on this. Albumin levels decrease earlier in patients that are going to develop more disorders during hospital stay.