Barbara Borkowska

Human body morphology, prevalence of nasopharyngeal potential bacterial pathogens, and immunocompetence handicap principal.

Body height, body mass index (BMI) and waist‐to‐hip ratio (WHR) are the main traits characterizing human body morphology. Studies show that these traits are related to attractiveness and, therefore, according to an evolutionary point of view, are supposed to be honest signals of biological quality. If the immunocompetence handicap principal (IHP) is true, people with more attractive values of these traits should be more immunologically competent. To test this, we analyzed whether nasal and throat colonization with potentially pathogenic bacteria is related to body height and BMI in both sexes and to WHR in females.

Leukocyte changes across menstruation, ovulation, and mid-luteal phase and association with sex hormone variation

Total leukocyte count (white blood cells—WBC) and the count of each subpopulation vary across the menstrual cycle, but results of studies examining the time and direction of these changes are inconsistent and methodologically flawed. Besides, no previous study focused on leukocyte count on the day of ovulation.

Recreational Drug Use and Fluctuating Asymmetry: Testing the Handicap Principle:

Zahavis handicap principle suggests that only organisms with good genetic quality can afford to engage in costly behaviors. Recreational drug use can be harmful to ones health and therefore might be viewed as a costly signal of ones genetic quality. One of the measurements of genetic quality is bodily symmetry assessed by fluctuating asymmetry. If unhealthy drug use is a behavioral example of Zahavis handicap principle, then men who use different stimulants or recreational drugs should be more symmetrical than men who do not use them at all or use them only in low quantity. The aim of this study was to examine the relationships between drug use and fluctuating asymmetry. The subjects were 190 young women and 202 young men. Six bilaterally symmetrical traits were measured: length of II–V digits, wrist breadth, and ear height. Questionnaires included questions about smoking, alcohol drinking, drug use, and designer drug use. There was no relationship between bodily symmetry and smoking frequency, alcohol drinking frequency, drug or designer drug use, total substance use, age of smoking initiation, or reason of this initiation. The results indicate that drug use does not reflect genetic quality and does not necessarily relate to the handicap hypothesis.

No evidence for the immunocompetence handicap hypothesis in male humans

The observations that testosterone might be immunosuppressive, form the basis for the immunocompetence handicap hypothesis (ICHH). According to ICHH only high-quality individuals can maintain high levels of testosterone and afford the physiological cost of hormone-derived immunosuppression. The animal and human studies that attempted to support the ICHH by precisely defined impairment of immunity associated with high testosterone levels are inconclusive. Furthermore, human studies have used only selected immune functions and varying testosterone fractions. This is the first study examining the relationship between multiple innate and adaptive immunity and serum levels of free testosterone, total testosterone, DHT and DHEA in ninety-seven healthy men. Free testosterone and marginally DHT levels were positively correlated with the strength of the influenza post-vaccination response. Total testosterone and DHEA showed no immunomodulatory properties. Our findings did not support ICHH assumptions about immunosuppressive function of androgens. In the affluent society studied here, men with higher levels of free testosterone could afford to invest more in adaptive immunity. Since the hormone-immune relationship is complex and may depend on multiple factors, including access to food resources, androgens should be treated as immunomodulators rather than implicit immunosuppressants.

Human body symmetry and immune efficacy in healthy adults: PAWLOWSKI et al.

OBJECTIVES More symmetric organisms are perceived as more attractive. Fluctuating asymmetry (FA) i.e. small, random deviations from perfect bilateral symmetry, is supposed to inform about developmental instability. According to the good genes hypothesis, a low level of FA is a putative cue to an organisms biological quality. An important aspect of this quality is the immune system functioning. The aim of this study was to evaluate the relationship between immune system functioning and body symmetry in healthy people. MATERIALS AND METHODS The composite body FA (cFA) was assessed on the basis of six bilateral traits (on hands and feet). The ISF was determined by many innate (total complement and lysozyme activity, neutrophils function) and adaptive immune parameters (T CD3 and B CD19 lymphocytes, total IgA and IgG and response to flu vaccine). A total of 98 men and 92 women were subjected to flu (among them 37 men and 30 women also to tetanus) vaccination. The blood samples were collected before and 4 weeks after the antigens exposure. Immunomodulatory factors: participants age, body fat, and free testosterone level, were controlled. RESULTS Apart from the weak positive association between CD3 or CD19 and cFA in men, we found no association between the level of body symmetry and the rest of the analyzed immune parameters for both sexes. DISCUSSION Our results are the opposite of the good genes hypothesis prediction and suggest that in western, healthy populations, human mate preferences for more symmetric bodies are not related to immune competence.

Body height and immune efficacy: testing body stature as a signal of biological quality

According to the good genes hypothesis and energy allocation theory, human adult body height may reflect biological quality. An important aspect of this quality is immune system functioning (ISF). The aim of this study was to evaluate the relationship between ISF and body height in healthy people. The ISF was determined by several important innate (total complement and lysozyme activity, neutrophil function) and adaptive immune parameters (lymphocytes, IgA and IgG, and response to the flu vaccine). Overall, 96 males and 97 females were subjected to flu vaccination, and of these, 35 males and 34 females were subjected to tetanus. Blood samples were collected before and four weeks after vaccination. Immunomodulatory factors, participants age, body fat, and free testosterone levels, were controlled. There was no association between body height and all analysed immune parameters for both sexes. That might suggest that in Western society, a womens preference for taller men is not related to ‘good genes for immune competence’. We propose the novel Immunity Priority Hypothesis that explains the lack of relationship between adult body stature and ISF. This hypothesis, however, does not contradict the signalling role of a mans body height as a morphological marker of biological quality.

Sex differences in the risk factors for Staphylococcus aureus throat carriage

HighlightsRisk factors for S. aureus throat carriage are sex‐specific.High body fat amount is a risk factor for S. aureus colonization in healthy men.High free testosterone level is a risk factor for colonization in healthy women. Background Male gender and adiposity are considered to be risk factors for Staphylococcus aureus carriage. We tested whether colonization is related to free testosterone (fT) level and adiposity, measured with body mass index (BMI) and body fat percentage (BFP), in healthy adults. Methods Blood sample and throat swabs were taken twice (at 4‐week intervals) from healthy men and women aged 18‐36 years. fT level, height, weight, and BFP were measured. Participants were classified as persistent carriers, intermittent carriers (excluded from the analyses), and noncarriers. The final sample was 152 participants: 85 men and 67 women. Results BFP, but not BMI, correlated positively with S aureus colonization (P = .02) in men. BMI became a significant predictor of carriage only when comparing groups within and above norms (P = .04). There was no relationship for BMI nor BFP in women. Higher fT level was related to persistent carriage (P = .02) in women, there was no relationship for fT level in men. Conclusion Risk factors for S aureus carriage are sex dependent. Within‐sex variation in colonization is related to fT level in women, whereas in men it is related to the amount of body fat.