Laboratory parameters in male and female older people

Abstract

Establish the correct reference range of the results of laboratory examinations, in dependence of biological variance, in particular age and gender of the subjects, and the clinical decision thresholds, become essential for a correct evaluation of the pathological conditions. The reference intervals are often based on young adult healthy individuals, but might be inadequate for the older population. The possible bias of an over-or under-estimation of laboratory data in long-living subjects regards about all laboratory diagnostic profiles (hematological, biochemical, and organ profiles). In extremely aged people (>90 years old and centenarians), available data related to hematological and biochemical reference parameters are really scarce and in certain cases biased by not univocal selection criteria, relatively low numbers of cases and unbalanced numbers between male and females with a prevalence of woman centenarians. On the contrary, sex-specific chromosome gene expression, age-related modification in hormone production social and environmental factors might impinge on differences of values for many laboratory analytes. In particular, hemoglobin (Hb) rate decreases in aging with decline more rapid in males but with very slight differences in extreme ages. Levels of circulating T-and B-cells and related subpopulation qualitative modifications are less pronounced in oldest-old women than in men, that, instead, have increased blood monocyte. Increased calcium and phosphate serum levels and decreasing albumin levels are more prominent in women. In males, a reduced activation of platelets activation by von Willebrand Factor (VWF) of has been observed. Kidney function and related functional parameters (glomerular filtration rate (GFR)) are reduced in oldest old but the higher creatinine increase has been observed in males. Both centenarian men and women have a serum IgA and IgG increase, decreased of platelet counts and plateletcrit, increased mean platelet volume, platelet distribution width, and platelet-large cell ratio. Paradoxically, these subjects show a decrease in hematic glucose and insulin alanine transpeptidase concentration and an increase in total cholesterol values and increasing concentration for ALP (more prevalent in women) and LDH. Considering that is really arduous to recruit the “normal population” among extremely aged, long living, population, different and innovative approaches to obtain available reference intervals (RI) might be proposed. Recently, author has been proposed the real-world data mining tool, based on data collected from a variety of internet sources as social media, wearable and mobile devices, electronic health records, product and disease registries, e-health services, to obtain the so-called continuous RI. This might be the ideal approach to evaluate analytic results of older-old patients and ensure high data quality and reliable findings, with a smoother and more accurate representation of individual conditions reducing the likelihood of false positive or negative results.