Bioimpedance assessment of body composition in the first adulthood period of somatic types residing in highland

The morphological assessment of the individual somatic type, morphotype, genotype, body type serves as its cardinal basis and as relevant element in the biomedical research fields and daily practice in the medical and nutritional science; body composition can be interpreted and measured according to five organizational levels including variables measurement such as fat mass (FM), fat-free mass (FFM), total body water (TBW), bone mineral content, intra (ICW), and extra cellular (ECW) fluids, and different anthropometric measurements and index [1–4]. The anatomical variability of the somatic types of various ethnic groups and nationalities has not been sufficiently studied [5–8]. One of the common methods of somatotypology is Sheldon’s scheme, which modifies Heath and Carter’s applicability for both genders of all nationalities and races in a wide age range [9, 10]. The main indicator of nutritional status is the body mass component composition (muscle, bone, fat, etc.). Bioimpedance analysis, as an operational, non-invasive and highly informative method, allows one to assess the condition of protein, fat, water and mineral metabolism [11–18].

In the literature, there is a lack of data on the physical status of a healthy person, concerning different age-sex criteria [19,20]. The first period of adulthood is maturity itself, characterized by the end of the growth processes, the relative stability of definitive parameters [21] and it reflects the indicators of the young, able-bodied, reproductive strata of the population [22].

However, there is no information on the somatotypological characteristics of healthy people in the first adulthood period, considering the body component composition of highland residing people in the Kyrgyz Republic. A comparative bioimpedance assessment of somatotypes and body composition for people living in the high and low mountain conditions has been performed. Studies on body composition using bioimpedanosometry according to Heath and Carter’s body diagrams were conducted during the first adulthood period Kyrgyz people with various somatotypes residing in the highland [23–25].

In this study, 208 healthy men living in highlands aged from 22 to 35 years old and permanently residing at an altitude of 2469 – 3325 m above the sea level, were examined. For comparison, 221 men living in Osh city at an altitude of 870 - 1110 m above sea level were also examined.

The purpose of the study is to perform bioimpedance comparative assessment of somatic types and body component composition among the first mature age period of people residing in the highland.

The main research findings were obtained after analysis of body component composition, bioimpedanocemetry, correlation analysis and the index method.

Data analysis after somatometric and bioimpedance studies on males living in the highlands showed differences in the ratios of three main groups. A significant proportion of the highland residing population consisted of individuals with endomorphic 46.154% (n = 96) and ectomorphic 32.692% (n = 68) body types. Cohorts of individuals with mesomorphic somatotypes were registered in 21.154% (n = 44) of males living in the highland. Table 1 and Figure 1 show information on quantitative relationships and distributions of somatotypes.

Fig.1:

Distribution of somatotypes of highlanders according to Heath B.H. and Carter J.E.

From the MM cohort, mesoectomorphy predominates (16.827%, n = 35), EcM – balanced ectomorphy (12.5%, n = 26), EnM – meso-endo (11.058%, n = 23), and the central body type in 9.135% (n = 19) of men.

Comparison of the anthropometric parameters of mesomorphic (MM) males residing in highlands with similar data from males residing in low mountains shows that the body length of city residents is significantly higher P<0.05 (3.6 cm), while body mass (BM) and chest circumference (CC) are not significantly different. In males with ectomorphic somatotype, comparison of all body dimensions with city residents did not reveal significant differences (P<0.5). In males with endomorphic somatotype living in highlands, chest circumference predominated (P<0.05), (Table 2).

The body surface area of the compared groups has not revealed significant differences. In men residing in the highland with mesomorphic somatotype, the body mass index (BMI) and waist-hip (W/H) ratios were predominated (Table 3). In endomorphic somatotypes, the W/H ratio is 1.82 times higher compared to the same indicators of city residents.

Bioimpedansometry revealed somototypological features of the body component composition parameters. Men living in highlands with endomorphic somatotype have a high content of absolute and relative active cell mass (ACM) and phase angle (PA) (P<0.05 – 0.01), with a low percentage of skeletal muscle mass (SMM). In 75% of EnM men living in highlands, the phase angle is increased by 1.12 times (8.3°, P<0.05), which indicates a high level of training and endurance [10, 17].

In men with endomorphic somatotype residing in the Osh city low mountainous area, there was an increase in the values of HFW (1.1 times), predominance of the skin fat fold (SFF) thickness in the shoulder area at the back, above the iliac crest and lower leg (P<0.01), with a relatively low value of weight, body length and body surface area (BSA). BMI in EnM for Osh city residents significantly exceeds the normal value (25.67–29.82 kg/m²), and 75% of people are diagnosed with excess body weight.

In males with ectomorphic somatotype living in the Osh city, in comparison with the highland ectomorphic somatotypes, the SMM predominated (1.03 and 1.028 times), HFW and WFA (1.07 and 1.06 times) predominated, and low values of PA by 0.71° (7.409±0.51), P<0.05 were found. In the highland residing men with ectomorphic somatotype, there are significant increases in the absolute and percentage contents of FM, ACM, BFM, active cell mass index (ACMI) and PA. The thickness of the SFF of the chest and anterior abdominal wall prevails p<0.05.

In men with mesomorphic somatotype in Osh, HFW and WFA were predominated. The phase angle exceeds normal values (7.99±0.056°, 8.6°, 3^rd quartile). Low FM content and % ACM content, P<0.05.

Men residing in highlands with mesomorpic somatotype have low SMM values, with high values of IFM, ACMI 1.26 and 1.05 times, BMI and PA 8.681±0.046°, 9.2°, 3^rd quartile, P<0.01. The majority of MM highland residing men (75%) have excess body weight, BMI is 25.9 kg/m², median, and the predominance of the abdominal wall thickness, the front shoulder 1.11 times and the anterior abdominal wall 1.24 times, 22 mm, 3^rd quartile.

Correlation analysis revealed variability in the strength and degree of relationship between the compared values. Positive correlations are often found between the variables: MT - DT; BMI – FM, %FM; OGK – waist circumference; ZhM – %ZhM; TM – ACM, SMM, VKZh; ACM – %ACM, OZH, VKZH; PA – %ACM, ACM; Coolant – VKZh (r = >0.7).

Negative – BMI – %SMM (r = - 0.73); ZhM – %SMM (r = - 0.81); TM – %FM (r = - 0.63); %FM – %SMM (r = - 0.85); %ACM – BMI (r = - 0.62).

Comparison of frequency in the main male somatotypes living in the highland and low mountains revealed differences in the frequency distributions of subtypes: increase in meso-endomorphic somatotype (16.29%), central form (12.67%) and ectoendomorphic somatotype (9.50%), with decrease in the proportion of mesoectomorphic somatotype to 8.6% (low mountains). Comparative bioimpedance and correlation analysis established differences in body composition indicators depending on populations, age, body types and living conditions. Low variation between study subjects in the body mass shown in table 2 may be due to lifestyle and same environmental conditions.