scholarly journals Diurnal Variation in the Core Interthreshold Zone in Women and its Sex Difference

2018 ◽  
pp. 26-37 ◽  
Author(s):  
Naoshi Kakitsuba ◽  
Igor B. Mekjavic
Keyword(s):  
Oxygen Uptake ◽  
Diurnal Variation ◽  
Sex Difference ◽  
Core Temperature ◽  
Diurnal Changes ◽  
Sweating Rate ◽  
Cutaneous Sensation ◽  
The Core ◽  
Male Subjects ◽  
Female Subjects

Background: The core interthreshold zone (CIZ) is defined as the range between core temperature (Tc) at the onset of shivering and the Tc at the onset of sweating under consistent mean skin temperatures of 28°C to 30°C. A previous study demonstrated a diurnal change in the CIZ for male subjects and its relationship to the cutaneous sensation threshold zone (CSZ). In the present study, diurnal changes in the CIZ and the CSZ for young Japanese female subjects were investigated using the same experimental protocol from the study of male subjects and the sex differences in these responses were then examined. Methods: The CIZ and the CSZ were measured in 10 female subjects who participated in three experiments in a single day during the morning, afternoon, and evening in the summer of 2014 (single-day experiment), and six female subjects who participated in the same experiments on the morning of day 1, the afternoon of day 2, and the evening of day 3 during the summer of 2016 (multiple-day experiment). Air temperature was controlled at 25°C. Each subject wore a suit perfused with 25°C water at a rate of 600 cc/min, and exercised at 50% of their maximum work rate on an ergometer for 10–15 min until their sweating rate increased. They then remained seated, without exercising, until their oxygen uptake increased. Rectal temperature, skin temperature at seven sites, the forehead-sweating rate, and oxygen uptake were continuously monitored throughout the experiment. Cutaneous warm and cold sensation thresholds were measured at three sites using 1-cm2 and 2-cm2 probes. Results: The results from the single-day experiment demonstrated that the CIZ was proportional to core temperature prior to exercise (Tc-init) whereas the results from the multiple-day experiment demonstrated that the CIZ increased continuously from morning to evening despite almost a constant Tc-init. The CIZ appeared to be proportional to the CSZ measured with the 2-cm2 probe. When compared with the results from the previous study of men, no significant sex difference was observed between the CIZ of 0.25±0.07°C for female subjects and 0.21±0.05°C for male subjects. Conclusion: No significant sex difference or diurnal variation in the CIZ was confirmed. Continuous increase in the CIZ from morning until evening is expected in both men and women under a normal Tc circadian rhythm.

Smiling in Photographs: Childhood Similarities between Sexes Become Differences Constant in Adulthood

2005 ◽  
Vol 97 (2) ◽  
pp. 651-665 ◽  
Author(s):  
Mark DeSantis ◽  
Philip J. Mohan ◽  
R. Kirk Steinhorst
Keyword(s):  
North America ◽  
Facial Expression ◽  
Sex Difference ◽  
Age Groups ◽  
School Age ◽  
Grade School ◽  
Male Subjects ◽  
Female Subjects

Contemporary published photographs of 1639 children, 200 older teenagers, and 304 adults in North America were analyzed for the smiling pattern (full, partial, or none) exhibited by individuals by sex. For each of the three age groups and for both sexes, most individuals posed with a full smile. No statistically significant differences in smiling pattern were present between the sexes for photographs of children at preschool and grade-school age. By teenage years, and even more for the adults, there were statistically significant differences between the sexes with regard to a smiling facial expression. In those cases, more female than male subjects smiled fully, whereas more male than female subjects did not smile. Examination of photographs of well-known persons longitudinally through adulthood showed that individuals tended to be consistent in smiling pattern. There was no significant sex difference for this relative constancy of facial expression in posed photographs.

Diurnal heart rate variability in healthy subjects: effects of aging and sex difference

1996 ◽  
Vol 271 (1) ◽  
pp. H303-H310 ◽  
Author(s):  
Y. Yamasaki ◽  
M. Kodama ◽  
M. Matsuhisa ◽  
M. Kishimoto ◽  
H. Ozaki ◽  
...  
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Sex Difference ◽  
Low Frequency ◽  
Frequency Domain Analysis ◽  
And Gender ◽  
Effects Of Aging ◽  
Parasympathetic Function ◽  
Male Subjects ◽  
Female Subjects

To study the effects of aging and gender, circadian profiles of heart rate variability were evaluated for 105 healthy volunteers by frequency domain analysis of a Holter electrocardiogram record. The low-frequency (LF) component representing cardiac beta-adrenergic function showed high values for the 0800-1200 period in male subjects and the 1200-2400 period in female subjects. The high-frequency (HF) component representing parasympathetic function showed a peak for the 0000-0600 period in both male and female subjects independent of age. Male subjects showed significantly higher %LF [LF/(LF + HF) x 100] than female subjects. LF showed consistently highly significant correlation with age. These basic findings can help elucidate the diurnal profile of cardiac nerve function and how it is affected by aging and sex difference.

Core temperature "null zone"

1991 ◽  
Vol 71 (4) ◽  
pp. 1289-1295 ◽  
Author(s):  
I. B. Mekjavic ◽  
C. J. Sundberg ◽  
D. Linnarsson
Keyword(s):  
Core Temperature ◽  
Recovery Period ◽  
Rest Period ◽  
Cycle Ergometer ◽  
Work Rate ◽  
The Core ◽  
Maximum Work ◽  
Male Subjects ◽  
Shivering Thermogenesis ◽  
Peak Value

An experimental protocol was designed to investigate whether human core temperature is regulated at a “set point” or whether there is a neutral zone between the core thresholds for shivering thermogenesis and sweating. Nine male subjects exercised on an underwater cycle ergometer at a work rate equivalent to 50% of their maximum work rate. Throughout an initial 2-min rest period, the 20-min exercise protocol, and the 100-min recovery period, subjects remained immersed to the chin in water maintained at 28 degrees C. On completion of the exercise, the rate of forehead sweating (Esw) decayed from a mean peak value of 7.7 +/- 4.2 (SD) to 0.6 +/- 0.3 g.m-2.min-1, which corresponds to the rate of passive transpiration, at core temperatures of 37.42 +/- 0.29 and 37.39 +/- 0.48 degrees C, as measured in the esophagus (Tes) and rectum (Tre), respectively. Oxygen uptake (VO2) decreased rapidly from an exercising level of 2.11 +/- 0.25 to 0.46 +/- 0.09 l/min within 4 min of the recovery period. Thereafter, VO2 remained stable for approximately 20 min, eventually increased with progressive cooling of the core region, and was elevated above the median resting values determined between 15 and 20 min at Tes = 36.84 +/- 0.38 degrees C and Tre = 36.80 +/- 0.39 degrees C. These results indicate that the core temperatures at which sweating ceases and shivering commences are significantly different (P less than 0.001) regardless of whether core temperature is measured within the esophagus or rectum.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Diurnal variation in the control of ventilation in response to rising body temperature during exercise in the heat

2016 ◽  
Vol 311 (2) ◽  
pp. R401-R409
Author(s):  
Bun Tsuji ◽  
Yasushi Honda ◽  
Narihiko Kondo ◽  
Takeshi Nishiyasu
Keyword(s):  
Diurnal Variation ◽  
Core Temperature ◽  
Time Course ◽  
Cold Water ◽  
Minute Ventilation ◽  
Peak Oxygen Uptake ◽  
Time Of Day ◽  
Control Of Ventilation ◽  
The Subject ◽  
Male Subjects

We investigated whether heat-induced hyperventilation during exercise is affected by time of day, as diurnal variation leads to higher core temperatures in the evening. Nineteen male subjects were divided into two experiments ( protocol 1, n = 10 and protocol 2, n = 9). In protocol 1, subjects performed cycle exercise at 50% peak oxygen uptake in the heat (37°C and 50% RH) in the morning (0600) and evening (1800). Results showed that baseline resting and exercising esophageal temperature ( Tes) were significantly (0.5°C) higher in the evening than morning. Minute ventilation (V̇e) increased from 54.3 ± 7.9 and 54.9 ± 6.8 l/min at 10 min to 71.4 ± 8.1 and 76.5 ± 11.8 l/min at 48.5 min in the morning and evening, respectively (both P < 0.01). Time of day had no effect on V̇e ( P = 0.44). When V̇e as the output response was plotted against Tes as thermal input, the Tes threshold for increases in V̇e was higher in the evening than morning (37.2 ± 0.7 vs. 36.6 ± 0.6°C, P = 0.009), indicating the ventilatory response to the same core temperature is smaller in the evening. In protocol 2, the circadian rhythm-related higher resting Tes seen in the evening was adjusted down to the same temperature seen in the morning by immersing the subject in cold water. Importantly, the time course of changes in V̇e during exercise were smaller in the evening, but the threshold for V̇e remained higher in the evening than morning ( P < 0.001). Collectively, those results suggest that time of day has no effect on time course hyperventilation during exercise in the heat, despite the higher core temperatures in the evening. This is likely due to diurnal variation in the control of ventilation in response to rising core temperature.

Effect of initial core temperature on hyperthermic hyperventilation during prolonged submaximal exercise in the heat

2012 ◽  
Vol 302 (1) ◽  
pp. R94-R102 ◽  
Author(s):  
Bun Tsuji ◽  
Yasushi Honda ◽  
Naoto Fujii ◽  
Narihiko Kondo ◽  
Takeshi Nishiyasu
Keyword(s):  
Relative Humidity ◽  
Oxygen Uptake ◽  
Core Temperature ◽  
Minute Ventilation ◽  
Water Immersion ◽  
Peak Oxygen Uptake ◽  
Submaximal Exercise ◽  
Temperature Threshold ◽  
Esophageal Temperature ◽  
Male Subjects

We investigated whether a core temperature threshold for hyperthermic hyperventilation is seen during prolonged submaximal exercise in the heat when core temperature before the exercise is reduced and whether the evoked hyperventilatory response is affected by altering the initial core temperature. Ten male subjects performed three exercise trials at 50% of peak oxygen uptake in the heat (37°C and 50% relative humidity) after altering their initial esophageal temperature (Tes). Initial Tes was manipulated by immersion for 25 min in water at 18°C (Precooling), 35°C (Control), or 40°C (Preheating). Tes after the water immersion was significantly higher in the Preheating trial (37.5 ± 0.3°C) and lower in the Precooling trial (36.1 ± 0.3°C) than in the Control trial (36.9 ± 0.3°C). In the Precooling trial, minute ventilation (V̇e) showed little change until Tes reached 37.1 ± 0.4°C. Above this core temperature threshold, V̇e increased linearly in proportion to increasing Tes. In the Control trial, V̇e increased as Tes increased from 37.0°C to 38.6°C after the onset of exercise. In the Preheating trial, V̇e increased from the initially elevated levels of Tes (from 37.6 to 38.6°C) and V̇e. The sensitivity of V̇e to increasing Tes above the threshold for hyperventilation (the slope of the Tes-V̇e relation) did not significantly vary across trials (Precooling trial = 10.6 ± 5.9, Control trial = 8.7 ± 5.1, and Preheating trial = 9.2 ± 6.9 L·min−1·°C−1). These results suggest that during prolonged submaximal exercise at a constant workload in humans, there is a clear core temperature threshold for hyperthermic hyperventilation and that the evoked hyperventilatory response is unaffected by altering initial core temperature.

THE EFFECT OF ALTERATION OF THYROXINE BINDING CAPACITY ON THE DIALYZABLE AND ABSOLUTE FRACTIONS OF TRIIODOTHYRONINE IN CIRCULATION

1973 ◽  
Vol 72 (2) ◽  
pp. 265-271 ◽  
Author(s):  
J. H. Dussault ◽  
D. A. Fisher ◽  
J. T. Nicoloff ◽  
V. V. Row ◽  
R. Volpe
Keyword(s):  
Correlation Coefficient ◽  
Inverse Relationship ◽  
Binding Capacity ◽  
Hormone Concentration ◽  
Thyroxine Binding Globulin ◽  
Serum Thyroxine ◽  
A Value ◽  
The Mean ◽  
Male Subjects ◽  
Female Subjects

ABSTRACT In order to determine the effect of alterations in binding capacity of thyroxine binding globulin (TBG) on triiodothyronine (T3) metabolism, studies were conducted in 10 patients with idiopathically low (7 subjects) or elevated (3 subjects) TBG levels and 10 subjects given norethandrolone (7 male subjects) or oestrogen (3 female subjects). Measurements of serum thyroxine (T4) concentration, maximal T4 binding capacity, serum T3 concentration and per cent dialyzable T3 were conducted. Serum T3 was measured both by chemical and radioimmunoassay methods. In patients with idiopathically low TBG, the mean serum T4 concentration was low (2.4 μg/100 ml), the mean serum T3 level low (55 ng/100 ml), the mean per cent dialyzable T3 increased (0.52%), and the calculated free T3 concentration normal (186 pg/100 ml). In patients with idiopathically high TBG levels the mean T4 concentration was high (10.3 μg/100 ml), the mean T3 level slightly elevated (127 ng/100 ml), the% dialyzable T3 low (0.10%) and the calculated free T3 concentration low normal (123 pg/100 ml). The correlation coefficient between the per cent dialyzable T3 and maximal TBG binding capacity in the 20 subjects was 0.68, a value significant at the P < 0.01 level. Thus, alterations in binding capacity of TBG seem to influence T3 and T4 metabolism similarly; the inverse relationship between the % of dialyzable hormone and total hormone concentration tends to keep the absolue levels of free hormones stable.

scholarly journals Mood and Metabolic Health Status of Elderly Osteoporotic Patients in Korea: A Cross-Sectional Study of a Nationally Representative Sample

Healthcare ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 77
Author(s):  
Hyen Chul Jo ◽  
Gu-Hee Jung ◽  
Seong-Ho Ok ◽  
Ji Eun Park ◽  
Jong Chul Baek
Keyword(s):  
Abdominal Obesity ◽  
Bone Health ◽  
Elderly Women ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Standard Procedures ◽  
Nationally Representative ◽  
Male Subjects ◽  
Female Subjects

This study aimed to investigate the association between osteoporosis and comorbidity, which are very common in Korea, and develop a treatment strategy to improve bone health based on the findings of the Korean National Health and Nutritional Examination Surveys (KNHANES). This study was based on data obtained from 4060 subjects (1755 males, 2305 females) aged above 60 years in the KNHANES (2016–2017). Well-trained medical staff performed the standard procedures and measured several variables including height, weight, and waist circumference. Interviews and laboratory tests were based on the diagnosis of hyperuricemia, dyslipidemia, type 2 diabetes mellitus (T2DM), osteoporosis, and depression. Comorbidities were defined as a self-reported physician diagnosis. The association of osteoporosis with depression and metabolic disease was assessed statistically using the complex sample analysis method of SPSS. The presence of osteoporosis, dyslipidemia, T2DM, hyperuricemia, obesity, abdominal obesity, and depression was 6.1 ± 0.5%, 15.2 ± 0.7%, 6.5 ± 0.4%, 13.4 ± 0.7%, 30.8 ± 0.8%, 19.4 ± 0.9%, 4.0 ± 0.2%, respectively. After adjusted by age, osteoporotic subjects were significance in the presence of abdominal obesity (p = 0.024, OR 0.80), hyperuricemia (p = 0.013, OR 0.68), dyslipidemia (p < 0.001, OR 1.84), and depression (p < 0.001, OR 2.56), respectively. Subgroup analyses showed dyslipidemia (female subjects, p < 0.001, OR 1.04; male subjects, p = 0.94, OR 1.09) and depression (female subjects, p < 0.001, OR 1.76; male subjects, p = 0.51, OR 0.62) were associated with osteoporotic female subjects but not in male subjects. The comorbidity of dyslipidemia and depression in female subjects was associated with osteoporosis and an odds ratio was 13.33 (95% CI: 8.58–20.71) (p < 0.001). The comorbidity of abdominal obesity (female subjects, p = 0.75, OR 0.97; male subjects, p = 0.94, OR 1.02) and hyperuricemia (female subjects, p = 0.27, OR 0.81; male subjects p = 0.07, OR 0.35) was not associated with osteoporosis in both Subgroup. The result of this study shows a strong dependency of comorbidity with dyslipidemia and depression in elderly women with osteoporosis. Therefore, efforts to improve dyslipidemia and depression might prevent compromised bone health.

scholarly journals Eating behavior affects cardio-metabolic risk in high school teenagers in a developing country

2020 ◽  
Vol 29 (1) ◽  
pp. 71-81
Author(s):  
Rita Suhadi ◽  
Phebe Hendra ◽  
Dita Maria Virginia ◽  
Christianus Heru Setiawan
Keyword(s):  
Risk Factors ◽  
Heart Rate ◽  
Waist Circumference ◽  
Eating Behavior ◽  
Eating Behaviors ◽  
Metabolic Risk Factors ◽  
Metabolic Risk ◽  
Cross Sectional ◽  
Male Subjects ◽  
Female Subjects

BACKGROUND Modernization negatively changes lifestyle, characterized by excessive eating and reduced energy consumption, and concurrently increases the cardiometabolic risk. This study was aimed to evaluate the association between eating behavior and cardio-metabolic risk factors including body mass index (BMI) in percentile, blood pressure (BP) in percentile, waist circumference, and heart rate in total subjects and gender sub-groups. METHODS This analytical cross-sectional study was done from July to November 2018. High schools in four provinces of Indonesia and students were selected using purposive sampling. Subjects’ profiles were collected from interview and cardio-metabolic parameters were measured at the study sites. Data were analyzed with chi-square and independent t-test. RESULTS Subjects who were overweight/obese and had high BP accounted for 27.1% and 9.3–12.0% of the total subjects (n = 768), respectively. Subjects who having breakfast tended to have lower BMI (p = 0.006), and the lower consumption of western meals had lower heart rate (p = 0.02). Male subjects had more meal frequency and had less quantity of snacks than female subjects (p<0.001). Male subjects with routine intake of vegetables had low heart rate (p = 0.03). Female subjects with routine breakfast had better BMI (p<0.001), and lower diastolic BP (p = 0.004) and waist circumference (p = 0.02), whereas those who consumed Western meals had higher heart rate (p = 0.046) and waist circumference (p = 0.001). CONCLUSIONS Eating behaviors are likely to affect cardio-metabolic risk factors, and the effects vary within gender groups.

The five‐factor personality model in applied settings

1994 ◽  
Vol 8 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Itzhak Montag ◽  
Joseph Levin
Keyword(s):  
Factor Analysis ◽  
Personality Inventory ◽  
The Other ◽  
Factor Solution ◽  
Male And Female ◽  
Neo Personality Inventory ◽  
Clear Cut ◽  
Five Factors ◽  
Male Subjects ◽  
Female Subjects

Two studies of the Revised NEO‐Personality Inventory (NEO‐PI‐R) conducted on two different applicant samples (one consisting of 539 female subjects and the other consisting of 396 male subjects) are reported. Factor analysis of the female sample yielded a five‐factor solution, highly congruent with the factors presented by Costa, McCrae and Dye (1991). Results of the male data were less clear‐cut, yielding four to five factors which were moderately congruent with the American data. The combined male and female sample showed again high congruence coefficients. Various minor deviations in the location of the facet variables are discussed.

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