Effects of circadian variation, lifestyle and environment on hematological parameters: A narrative review

Abstract

The complete blood count (CBC) is the most widely prescribed laboratory test. It plays a key role in screening, diagnosing, and monitoring a variety of medical disorders. Preanalytical and analytical variables are responsible for more than 50% of laboratory errors that may lead to spurious CBC results. The effects of blood sampling, transport, storage, and analytical errors on hematological parameters have been well described. Circadian variation and changes in lifestyle and environment can also affect blood cells. It has been extensively studied in the past, but highly variable methodology and the presence of confounding factors have provided scattered and inconsistent results. We have investigated the literature to define the impact of circadian variation, modification of the sleep‐wake cycle, acute and chronic exercise, eating habits, alcohol, tobacco, drugs of abuse, high‐altitude, heat/cold exposure, and air pollution on CBC results. The affected cell type along with the intensity and duration of changes are detailed for each condition. We aim at providing a comprehensive overview of which situations may induce clinically significant changes and have to be taken into account by healthcare professionals before considering a hematological parameter as pathological and requesting complementary tests.

Application of haematology parameters for health management in fish farms

“…Therefore, haematology parameters in fish could also reflect alterations in internal and external factors such as changes in aquaculture water, interspecific competition, nutrient deficiency and pathogen invasion. 7,8 A growing body of evidence has demonstrated that the characteristics of fish haematology could accurately reflect age, sex, reproductive efficiency and culture environment, among other factors. 5,9,10 Therefore, haematological parameters can provide important insights into the real-time health status of fish.…”

“…29 For instance, haematocrit, counts of RBC and haemoglobin concentration are the most easily evaluated and most commonly used haematological parameters in field conditions such as ponds. 8 Among different haematologic parameters, haematocrit does not vary as readily as other parameters and could be used in combination with counts of RBC and white blood cells, haemoglobin concentration, erythrocyte osmotic fragility and differential leukocyte count. 27 Additionally, the characteristics of RBC determine, at least partially, the efficiency of oxygen transport from the surface of RBC to tissues, and the changes in their quantity and volume also affect metabolic performance.…”

“…Blood tests are widely used for diagnosis in humans and show a clear correlation between the real‐time health status of patients and causative factors. Therefore, haematology parameters in fish could also reflect alterations in internal and external factors such as changes in aquaculture water, interspecific competition, nutrient deficiency and pathogen invasion 7,8 . A growing body of evidence has demonstrated that the characteristics of fish haematology could accurately reflect age, sex, reproductive efficiency and culture environment, among other factors 5,9,10 .…”

Variation in the sexual behavior and blood count parameters induced by sleep deprivation in male rats

“…25 While white blood cell count (WBC) is a useful inflammatory marker in clinical applications, neutrophils mainly mediate the innate immune response, secreting inflammatory mediators and cytokines, and lymphocytes mediate the adaptive immune response by regulating inflammation. 26 Sleep and sleep deprivation have been shown to have an impact on blood cell count. 27 Whereas the neutrophil-to-lymphocyte ratio (NLR) is associated with erectile dysfunction in men.…”

“…In daily clinical practice, hematological parameters in complete blood count (CBC) are a frequently used, simple, and inexpensive laboratory method 25 . While white blood cell count (WBC) is a useful inflammatory marker in clinical applications, neutrophils mainly mediate the innate immune response, secreting inflammatory mediators and cytokines, and lymphocytes mediate the adaptive immune response by regulating inflammation 26 . Sleep and sleep deprivation have been shown to have an impact on blood cell count 27 .…”