OBJECTIVELeptin is an adipocyte-derived hormone regulating body weight and energy balance in animals and human being. Although the physiological functions of leptin in human are still unclear, its secretion is closely related to fat mass and energy expenditure in both adults and children. This study investigated whether the plasma leptin level was reduced in connection with the weight loss during the neonatal period and try to find out the role of leptin in body weight regulation and energy balance of premature infants.

METHODSThe radioimmunoassay was used to determine the plasma leptin concentration. The first blood samples were obtained at the delivered, and then collected the samples every two days until the infants' body weight recovered to the birth weight or above. At the same time, the essential fluid and energy for the patients were supplied to keep their physiological functions. One person was appointed to take responsibility to examine the body weight, body length and head circumference. Then computed out their Kaup index from the first day to the seventh or twelfth day.

RESULTSA total of 26 premature infants were selected into the study, of which 14 cases were male and 12 female, and their gestational age ranged from 30 to 36 weeks. There was a significantly positive correlation between the premature newborns' body weight loss and their plasma leptin levels (the 1st day: n = 26, r = 0.766; the 3rd day: n = 26, r = 0.636; the 5th day: n = 26, r = 0.629; the 7th day: n = 26, r = 0.717; the 9th-12th day: n = 24, r = 0.587; P < 0.01). The time of body weight loss and the plasma leptin level which declined to extremely low were positively correlated. (r = 0.611, P < 0.01). The time when body weight loss declined to extremely low in 26 premature infants ranged form the 3rd to the 9th day after birth [(5.2 +/- 1.6) day], and that of the plasma leptin levels ranged form the 3rd to the 8th day after birth (4.7 +/- 1.4) day. The maximal ranges of the body weight loss and the plasma leptin decrease in 26 premature infants were (6.5 +/- 3.0)% and (59.6 +/- 11.3)%, respectively. In addition, there were significantly positive correlations among the plasma leptin level, the premature newborns' body length (the 1st day: n = 26, r = 0.609, P < 0.01; the 3rd day: n = 26, r = 0.419, P < 0.05; the 5th day: n = 26, r = 0.583, P < 0.01; the 7th day: n = 26, r = 0.626, P < 0.01; the 9th-12th day: n = 24, r = 0.482; P < 0.05), and the Kaup index (the 1st day: n = 26, r = 0.634; the 3rd day: n = 26, r = 0.534; the 5th day: n = 26, r = 0.542; the 7th day: n = 26, r = 0.611; the 9th-12th day: n = 24, r = 0.539; P < 0.01). Although the head circumference correlated positively with the plasma leptin level at the first week after the delivery (the 1st day: n = 26, r = 0.580, P < 0.01; the 3rd day: n = 26, r = 0.417, P < 0.05; the 5th day: n = 26, r = 0.426; P < 0.01). There was a lower correlation between them one week after the delivery (the 7th day: n = 26, r = 0.369; the 9th-12th day: n = 24, r = 0.323; P > 0.05).

CONCLUSIONThere was a significantly positive correlation between the plasma leptin level and the premature newborns weight loss. Leptin may participate in the regulation of energy balance and body weight of premature infants during neonatal life. Leptin may play an important role in growth and development of premature infants.

Body Weight ; physiology ; Humans ; Infant, Newborn ; Infant, Premature ; Leptin ; blood ; Radioimmunoassay ; Time Factors ; Weight Loss ; physiology

Adult ; Birth Weight ; Body Mass Index ; Female ; Gestational Weight Gain ; physiology ; Humans ; Labor, Obstetric ; physiology ; Pregnancy

OBJECTIVESThe investigation of the testicular volume, the penis length and the T, FSH, LH, PRL levels in serum were taken in 289 adolescent males to provide the valuable data for andrology.

METHODSThe adolescent males were grouped according to their age. The testicular volume was measured with testicular model and the T, FSH, LH, PRL levels in serum were determined by immunoenzymetric assay.

RESULTSThe male sexual development was rapid from age 11 to 16 and close to that of adult at age 18. Serum PRL of adolescent males was higher than that of adult males.

CONCLUSIONSThe age 11 to 16 is a period of rapid growth in sexual maturation. PRL may play an important role in sexual maturation.

Adolescent ; Body Height ; Body Weight ; Gonadal Steroid Hormones ; blood ; Humans ; Male ; Penis ; physiology ; Testis ; physiology

OBJECTIVESTo investigate the development and the health of reproductive organs of male children and juvenile between the Meng and the Han nationality in the Meng nationality area.

METHODSMale juvenile(4-18 years old) of the Meng nationality (n = 2,315) and the Han nationality (n = 2,832) were divided into four age groups. Height, weight, length and perimeter of penis, volume of left and right testis and reproductive organs illness were examined.

RESULTSIn 13-18 years group, the developmental speed of reproductive organs was faster in Mongolia male juvenile than that in the Han nationality (P < 0.02). After 13 years old, the developmental speed of reproductive organs of male living in town is faster than that in the country (P < 0.05). Illness of male reproductive organs was common such as hernia, varicocle etc.

CONCLUSIONSThere was difference of developmental status and the prevalence rate of reproductive organs of male children and juvenile between the Meng and the Han nationality.

Adolescent ; Body Height ; Body Weight ; Child ; Child, Preschool ; China ; ethnology ; Humans ; Male ; Penis ; physiology ; Testis ; physiology

BACKGROUND: The Shanghai growth standards are higher than World Health Organization (WHO) growth standards, which may influence the feeding practices of the caregivers and increase the risk of overweight in these infants. This study aimed to compare the effects of different growth standards on childhood obesity in Shanghai metropolitan area. METHODS: This was a cluster-randomized controlled trial conducted in 2 downtown areas with 19 community health service centers in Shanghai from November 2013 to December 2015. Randomization was done at the level of the community. Infants (health newborns) were assessed and monitored by the Shanghai growth standards (S-group) and the 2006 WHO growth standards (W-group), respectively. Measurements were taken at 1.0, 2.0, 4.0, 6.0, 9.0 and 12.0 months of age during follow-up period. Based on the values of length and weight measurements, according to the group's growth standards, doctors provided the caregivers with corresponding clinical consultation. Changes in weight-for-age z-score (WAZ), length-for-age z-score (LAZ), and weight-for length z-score (WLZ) between 2 groups were assessed using mixed regression models. Overweight was compared between 2 group at all follow-up measurements. RESULTS: A total of 6509 infants (52.1% were boys) were in the W-group, and 8510 infants (51.4% were boys) were in the S-group. The overweight ratios between two groups were distinct at 9 months of age (3.4% in W-group and 4.3% in S-group) and 12 months of age (2.2% in W-group and 3.8% in S-group), and the differences were statistically significant (P = 0.020 and P < 0.001, respectively). Compared to W-group, the increase in WAZ (coefficient = 0.04, P = 0.004) and WLZ (coefficient = 0.09, P < 0.001) were significantly greater, and the LAZ was lower (coefficient = -0.04, P = 0.047) in S-group (W-group values were used as reference in mixed regression models). CONCLUSION: Compared to the Shanghai growth standards, the adoption of WHO 2006 growth standards would reduce the risk of infant overweight in Shanghai metropolitan area up to 1 year of age. TRIAL REGISTRATION NUMBER ChiCTR1800015371, http://www.chictr.org.cn/ Chinese Clinical Trial Registry.
Body Height ; physiology ; Body Weight ; physiology ; China ; Feeding Behavior ; physiology ; Female ; Humans ; Infant ; Infant, Newborn ; Male ; Overweight ; physiopathology

OBJECTIVESTo study the roles of leptin in the development during puberty in girls and the its relationship with insulin (INS), growth hormone (GH), estradiol (E(2)) and testosterone (T).

METHODSOne hundred and fifty girls with simple obese aged 7 to 17 years, and 150 normal healthy girls and 150 girls with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E(2) and T were measured for them.

RESULTSTheir serum level of leptin positively correlated with body mass index (BMI) and age. Serum level of leptin in girls increased steadily from Tanner stage B(1) to stage B(5). At Tanner stage B(2), serum level of leptin in the normal groups (7.72 microg/L) was not significantly different from that in those with malnutrition (7.36 microg/L), but significantly lower than that in the obese groups (12.85 microg/L). At other Tanner stages, there was significant difference in serum level of leptin among obese, normal and malnutrition groups. Serum level of leptin correlated negatively with serum GH and positively with serum INS, but not correlated with E(2) and T.

CONCLUSIONSLeptin may play a role in triggering development during puberty in girls. Serum level of leptin at Tanner stage B(2) may be the threshold dose to trigger the onset of puberty in girls. Quickly increasing level of leptin at Tanner stage B(5) may inhibit the increase of GH, which ushered the end of puberty in girls.

Adolescent ; Body Height ; physiology ; Body Mass Index ; Body Weight ; physiology ; Child ; Female ; Growth Hormone ; metabolism ; Humans ; Leptin ; blood ; physiology ; Puberty ; physiology ; Testosterone ; metabolism

OBJECTIVESTo study the role of leptin in the development boys during their puberty and its relationship with insulin (INS), growth hormone (GH), estradiol (E2) and testosterone (T).

METHODSOne hundred and fifty boys with simple obese aged 7 to 17 years, 150 normal healthy boys and 150 boys with malnutrition matched for age (+/- 3 months) and height (+/- 2 cm) were selected. Serum levels of leptin, INS, GH, E2 and T were measured for them.

RESULTSSerum level of leptin in obese group was significantly higher than that in normal group, and that in normal group was significantly higher than that in malnourished group. In the all three groups, serum level of leptin increased with age first until peak value, then began to decrease, with peak value of 6.96 microg/L at ages of 10-11 y in obese group, 10.25 microg/L at ages of 11-12 y in normal group and 5.08 microg/L at ages of 11-12 y in malnourished group. Serum level of leptin increased steadily from Tanner stages G1 to G2, then began to decrease steadily in G2 to G4. Serum level of leptin increased again in stage G5. Serum level of INS in boys increased steadily with age from 7 to 17 years old. Serum levels of GH, T and E2 in boys began to increase since 10-11 years old. Serum level of leptin positively correlated with serum level of INS and negatively correlated with serum levels of GH and T, but not correlated with serum level of E2.

CONCLUSIONSLeptin may promote pubertal development of boys, but not the determinant factor in triggering and maintaining their pubertal development. Re-increase in level of leptin during stage G5 could inhibit secretion of GH, and signalize the end of puberty in boys.

Adolescent ; Body Height ; physiology ; Body Mass Index ; Body Weight ; physiology ; Child ; Estradiol ; metabolism ; Growth Hormone ; metabolism ; Humans ; Leptin ; blood ; physiology ; Male ; Puberty ; physiology ; Testosterone ; metabolism

Weight loss is frequently observed after acute exposure to high altitude. However, the magnitude and rate of weight loss during acute exposure to high altitude has not been clarified in a controlled prospective study. The present study was performed to evaluate weight loss at high altitude. A group of 120 male subjects [aged (32±6) years] who worked on the construction of the Golmud-Lhasa Railway at Kunlun Mountain (altitude of 4 678 m) served as volunteer subjects for this study. Eighty-five workers normally resided at sea level (sea level group) and 35 normally resided at an altitude of 2 200 m (moderate altitude group). Body weight, body mass index (BMI), and waist circumference were measured in all subjects after a 7-day stay at Golmud (altitude of 2 800 m, baseline measurements). Measurements were repeated after 33-day working on Kunlun Mountain. In order to examine the daily rate of weight loss at high altitude, body weight was measured in 20 subjects from the sea level group (sea level subset group) each morning before breakfast for 33 d at Kunlun Mountain. According to guidelines established by the Lake Louise acute mountain sickness (AMS) consensus report, each subject completed an AMS self-report questionnaire two days after arriving at Kunlun Mountain. After 33-day stay at an altitude of 4 678 m, the average weight loss for the sea level group was 10.4% (range 6.5% to 29%), while the average for the moderate altitude group was 2.2% (-2% to 9.1%). The degree of weight loss (Δ weight loss) after a 33-day stay at an altitude of 4 678 m was significantly correlated with baseline body weight in the sea level group (r=0.677, P<0.01), while the correlation was absent in the moderate altitude group (r=0.296, P>0.05). In the sea level subset group, a significant weight loss was observed within 20 d, but the weight remained stable thereafter. AMS-score at high altitude was significantly higher in the sea level group (4.69±2.48) than that in the moderate altitude group (2.97±1.38), and was significantly correlated with baseline body weight. These results indicate that (1) the person with higher body weight during stay at high altitude loses more weight, and this is more pronounced in sea level natives when compared with that in moderate altitude natives; (2) heavier individuals are more likely to develop AMS than leaner individuals during exposure to high-altitude hypoxia.
Adult ; Altitude ; Altitude Sickness ; physiopathology ; Body Mass Index ; Body Weight ; China ; Humans ; Hypoxia ; physiopathology ; Male ; Weight Loss ; physiology

OBJECTIVES: To investigate the link between cigarette smoking and muscle strength in Japanese men. METHODS: We used data on 4249 Japanese men, aged 43.3+/-13.9 years, in this cross-sectional investigation study. Grip strength and leg strength were measured as indicators of overall muscle strength. Meanwhile, subjects' cigarette smoking habits were recorded by trained medical staff. The effect of cigarette smoking on muscle strength was evaluated. RESULTS: A total of 1618 men (38.1%) were smokers and 1481 men (34.9%) exercised regularly. Significant differences in muscle strength were noted between men with and without a Brinkman index of 400 or greater, after adjusting for age. After adjusting for age, height, body weight and exercise habits, associations between the Brinkman index and leg strength and the ratio of leg strength to body weight were attenuated. CONCLUSIONS: Cigarette smoking might be negatively associated with muscle strength, especially grip strength in Japanese men.
Adult ; Body Weight ; Exercise ; Hand Strength/physiology ; Humans ; Japan ; Male ; Middle Aged ; Muscle Strength/*physiology ; *Smoking

Sixty clinically normal German shepherd dogs, 31 males and 29 females, ranging in age from 1 and 5 years and with a body weight ranging from 22 to 37.2 kg, were examined by the two-dimensional mode, M-mode, and Doppler echocardiography. In Doppler mode, the mitral valve flows were obtained, where the aim was to determine the velocity peaks and ratios of the E and A waves and the mitral E wave deceleration time. The velocity peaks were obtained for the tricuspid, pulmonary and aortic valves. On the left ventricular outflow tract flow, the time velocity integral and aortic cross-sectional area was used to calculate the cardiac output. A statistically significant correlation with the body weight was found for the systolic left atrial and diastolic aortic diameter on twodimensional mode. On M-mode, there was a significant correlation between the body weight and the systolic left atrium and diastolic aortic dimension, systolic and diastolic left ventricular, septal and posterior wall dimensions. Doppler echocardiography showed that there was no significant correlation between the body weight and the mitral, tricuspid, pulmonary and aortic valves flows. These results demonstrate that it is important to know the normal echocardiographic values for German shepherd dogs because there are some characteristics peculiar to this particular breed. The data obtained is expected to be helpful for studies on small animal cardiology.
Animals ; Body Weight ; Dogs/*physiology ; Echocardiography/*veterinary ; Female ; Heart/anatomy&histology/*physiology ; Male ; Sex Characteristics