Body weight and body composition during sixty days of isolation

Lifestyle Changes during the SARS-CoV-2 Pandemic as Predictors of BMI Changes among Men and Women in Poland

BACKGROUND

Social isolation during the SARS-CoV-2 pandemic affected people's body weight, therefore, this study was designed to evaluate the association between lifestyle elements and the change in BMI during lockdown.

METHODS

This retrospective observational study involved 290 questionnaires completed by adult participants divided into three groups according to BMI change during isolation. The structured questionnaire included a general description of the study objective and collected data regarding sociodemographics, anthropometrics, physical activity, sedentary behaviour, sleep duration, and food intake pre- and during COVID-19 lockdown.

RESULTS

A decrease or increase in BMI was found in 23.6% and 47.8% of women and 18.5% and 42.6% of men, respectively. Among those who lost weight, 46.5% of women and 40% of men followed a diet of their own choice, 30.2% of women and 25% of men changed their product mix and reduced their intake, 40% of men stopped eating outside the home. An increase in BMI was associated with increased food intake (32.2% of women and 28.3% of men), increased sleep duration on weekdays (49.2% of women and 43.5% of men) and, in more than 50% of subjects, decreased physical activity. In women, increased BMI was associated with the highest frequency of snacking (p = 0.0003), the highest intake of sweets (p = 0.0021), and in men with the highest intake of alcohol (p = 0.0017).

CONCLUSIONS

The observed changes in BMI during social isolation were the result of lifestyle modifications including dietary behaviour and differed by gender.

Adaptation of the main peripheral artery and vein to long term confinement (Mars 500)

Purpose

The objective was to check if 520 days in confinement (MARS 500), may affect the main peripheral arterial diameter and wall thickness and the main vein size.

Method

Common carotid (CC) femoral artery (FA) portal vein (PV), jugular (JG), femoral vein (FV) and tibial vein were assessed during MARS 500 by echography, performed by the subjects. A hand free volumic echographic capture method and a delayed 3D reconstruction software developed by our lab were used for collecting and measuring the vascular parameters.

Results

During the MARS 500 experiment the subjects performed 6 sessions among which 80% of the echographic data were of sufficient quality to be processed. No significant change was found for the Common carotid, Jugular vein, femoral artery, femoral vein, portal vein, and tibial vein diameter. CC and FA IMT (intima media thickness) were found significantly increased (14% to 28% P<0.05) in all the 6 subjects, during the confinement period and also at +2 days after the confinement period, but there was no significant difference 6 month later compare to pre MARS 500.

Conclusion

The experiment confirmed that even untrained to performing echography the subjects were able to capture enough echographic data to reconstruct the vessel image from which the parameters were measured. The increase in both CC and FA IMT should be in relation with the stress generated by the confined environment or absence of solar radiation, as there was no change in gravity, temperature and air in the MARS 500 module, and minor changes in physical exercise and nutrition.

Hormonal changes during long-term isolation

Confinement and inactivity induce considerable psychological and physiological modifications through social and sensory deprivation. The aim of the SFINCSS-99 experiment was to determine the cardiovascular and hormonal pattern of blood volume regulation during long-term isolation and confinement. Simulation experiments were performed in pressurized chambers similar in size to the volumes of modern space vehicles. Group I consisted of four Russian male volunteers, who spent 240 days in a 100-m(3 )chamber. Group II included four males (one German and three Russians) who spent 110 days in isolation (200-m(3) module). The blood samples, taken before, during and after the isolation period, were used to determine haematocrit (Ht), growth hormone (GH), active renin, aldosterone, and osmolality levels. From the urine samples, electrolytes, osmolality, nitrites, nitrates, cortisol, antidiuretic hormone (ADH), aldosterone, normetanephrine and metanephrine levels were determined. The increase in plasma volume (PV) that is associated with a tendency for a decrease in plasma active renin is likely to be due to decreased sympathetic activity, and concords with the changes in urinary catecholamine levels during confinement. Urinary catecholamine levels were significantly higher during the recovery period than during confinement. This suggests that the sympathoadrenal system was activated, and concords with the increase in heart rate. Vascular resistance is determined by not only the vasoconstrictor but also vasodilator systems. The ratio of nitrite/nitrate in urine, as an indicator of nitric oxide release, did not reveal any significant changes. Analysis of data suggests that the duration of the isolation was a main factor involved in the regulation of hormones.