scholarly journals Urea kinetics in healthy young women: minimal effect of stage of menstrual cycle, contraceptivepill and protein intake

1996 ◽  
Vol 76 (2) ◽  
pp. 199-209 ◽  
Author(s):  
Irene S. M. McClelland ◽  
Alan A. Jackson

Urea kinetics were measured using prime/lintermittent oral doses of [15N15N]urea, on five separate protocols in thirteen normal young women. Each woman underwent either two or three study protocols.Measurements were made at day 12 and day 22 of the menstrual cycle, whilst consuming their habitual protein intake in seven women not taking the contraceptive pill and in six women taking the contraceptive pill. In three woman taking the pill, and three not taking the pill, urea kinetics were measured whilst taking a diet in which the intakewas restricted to 55 g protein/d. There was no difference in the rate of urea production, urea excretion or urea hydrolysis between the women taking the pill and those not taking the pill at day 22. In the women not taking the pill there was no difference in any measure between day 12 and day 22. In the women taking the pill there was a significant difference in the disposal of urea N to excretion or hydrolysis on day 12 compared with day 22, with a relative decrease in excretion and enhancement of hydrolysis at day 12 compared with day 22. On the restricted diet, an intake of 55 g protein/d represented 77% of the habitual intake and urea production, excretion and hydrolysis were reduced to about 84% of the rate found on the habitual intake. In paired studies the reduction in urea production was statistically significant, and there was a statistically significant linear relationship between urea production and either intake or the sum of intake plus hydrolysis. The within-individual variability for urea production was about 10% for excretion 15% and for hydrolysis 44% The between-individual variability for intake was about 17% on the habitual intake. The variability for production, excretion and hydrolysis (14, 13, 36%) was less in the women not taking the contraceptive pill than in those taking the pill (23,32,42% respectively). The variability was reduced on the controlled low intake of 55 g protein compared with the habitual intake.These results confirm the wide variability in aspects of urea kinetics between individuals. In women this variability is not, to any large extent, accounted for by changes associated with themenstrual cycle

1999 ◽  
Vol 276 (5) ◽  
pp. E964-E976 ◽  
Author(s):  
Anders H. Forslund ◽  
Antoine E. El-Khoury ◽  
Roger M. Olsson ◽  
Anders M. Sjödin ◽  
Leif Hambraeus ◽  
...  

Effects of moderate physical activity (90 min at 45–50% of maximal O2 uptake 2 times daily) and “high” (2.5 g protein ⋅ kg−1 ⋅ day−1, n = 6) or “normal” protein intake (1.0 g protein ⋅ kg−1 ⋅ day−1, n = 8) on the pattern and rate of 24-h macronutrient utilization in healthy adult men were compared after a diet-exercise-adjustment period of 6 days. Energy turnover (ET) was determined by indirect and direct (suit) calorimetry, and “protein oxidation” was determined by a 24-h continuous intravenous infusion of [1-13C]leucine. Subjects were in slight positive energy balance during both studies. Protein contributed to a higher (22 vs. 10%) and carbohydrate (CHO) a lower (33 vs. 58%) proportion of total 24-h ET on the high- vs. normal-protein intake. The highest contribution of fat to ET was seen postexercise during fasting (73 and 61% of ET for high and normal, respectively). With the high-protein diet the subjects were in a positive protein ( P < 0.001) and CHO balance ( P < 0.05) and a negative fat balance ( P < 0.05). The increased ET postexercise was not explained by increased rates of urea production and/or protein synthesis.


1998 ◽  
pp. 190-194 ◽  
Author(s):  
T Teirmaa ◽  
V Luukkaa ◽  
J Rouru ◽  
M Koulu ◽  
R Huupponen

OBJECTIVE: Leptin is the hormonal product of the ob gene. It is expressed in adipocytes and participates in the regulation of food intake and metabolism. Since leptin also seems to signal metabolic information to the reproductive system, we studied the association between reproductive hormones and plasma leptin in normal-weight young women. DESIGN: Eight young women with normal menstrual cycles (body mass index (BMI) 21.2 +/- 1.6 kg/m2) and eight young women using hormonal contraception (BMI 21.4 +/- 1.1 kg/m2) were studied. Furthermore, six women with normal menstrual cycles and no hormonal therapy (BMI 20.7 +/- 1.2 kg/m2) were studied around the time of the anticipated ovulation. METHODS: Serum leptin, estradiol, progesterone and luteinizing hormone (LH) concentrations were measured with radioimmunoassays. RESULTS: Serum leptin concentrations were similar at the beginning of the cycle, at the time of the anticipated ovulation and at the end of the menstrual cycle (10.2 +/- 7.1, 10.7 +/- 7.0 and 11.8 +/- 6.9 microg/l respectively). There was an association between leptin and LH concentrations (r= 0.37, P< 0.01) when values recorded during different time points during the cycle were plotted with each other. There was no change in serum leptin in samples taken at different times of the cyclic treatment with an oral contraceptive. There was no significant difference in mean serum leptin concentrations between women using oral contraceptives and women with no hormonal therapy. CONCLUSIONS: There is a link between serum leptin and LH concentrations during the menstrual cycle. Variations in circulating estrogen and/or progesterone concentrations have no major influence on circulating leptin in young female subjects.


1997 ◽  
Vol 77 (2) ◽  
pp. 165-181 ◽  
Author(s):  
Irene S. M. McClelland ◽  
Chandarika Persaud ◽  
Alan A. Jackson

Urea kinetics were measured in normal women aged 22-34 years at weeks 16, 24 and 32 on either their habitual protein intake (HABIT.) or a controlled intake of 60 g protein/d (CONTROL), using primed-intermittent oral doses of [15N15N]urea and measurement of plateau enrichment in urinary urea over 18 h (ID) or a single oral dose of [15N15N]urea and measurement of enrichment of urea in urine over the following 48 h (SD). The intake of protein during HABIT-ID (80 g/d) was greater than that on HABIT-SD (71 g/d); urea production as a percentage of intake was significantly greater at week 16 for HABIT-ID than HABIT-SD, whereas urea hydrolysis at week 16 was greater for HABIT-SD than HABIT-ID and urea excretion at week 32 was greater for HABIT-ID than HABIT SD. The combined results for HABIT-ID and HABIT-SD showed a significant reduction in urea production at week 32 compared with week 24. Urea excretion decreased significantly from week 16 to week 24 with no further decrease to week 32 and urea hydrolysis was significantly greater at week 24 than either week 16 or week 32. Compared with HABIT, on CONTROL there was a decrease in urea production at week 16, and urea excretion was significantly reduced at week 16. For all time periods urea production was closely related to the sum of intake plus hydrolysis. Hydrolysis was greatest at week 24 and closely related to urea production. There was a significant inverse linear relationship overall for hydrolysis as a proportion of production and excretion as a proportion of intake. The results show that on HABIT N is more effectively conserved in mid-pregnancy through an increase in urea hydrolysis and salvage, and during late pregnancy through a reduction in urea formation. Lowering protein intake at any stage of pregnancy increased the hydrolysis and salvage of urea. The staging of these changes was later than that in pregnancy in Jamaica.


Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1159
Author(s):  
Stefanie M. P. Kouwenhoven ◽  
Manja Fleddermann ◽  
Martijn J. J. Finken ◽  
Jos W. R. Twisk ◽  
Eline M. van der Beek ◽  
...  

Background: High protein intake in early life is associated with an increased risk of childhood obesity. Dietary protein intake may be a key mechanistic modulator through alterations in endocrine and metabolic responses. Objective: We aimed to determine the impact of different protein intake of infants on blood metabolic and hormonal markers at the age of four months. We further aimed to investigate the association between these markers and anthropometric parameters and body composition until the age of two years. Design: Term infants received a modified low-protein formula (mLP) (1.7 g protein/100 kcal) or a specifically designed control formula (CTRL) (2.1 g protein/100 kcal) until 6 months of age in a double blinded RCT. The outcomes were compared with a breast-fed (BF) group. Glucose, insulin, leptin, IGF-1, IGF-BP1, -BP2, and -BP3 levels were measured at the age of 4 months. Anthropometric parameters and body composition were assessed until the age of 2 years. Groups were compared using linear regression analysis. Results: No significant differences were observed in any of the blood parameters between the formula groups (n = 53 mLP; n = 44 CTRL) despite a significant difference in protein intake. Insulin and HOMA-IR were higher in both formula groups compared to the BF group (n = 36) (p < 0.001). IGF-BP1 was lower in both formula groups compared to the BF group (p < 0.01). We found a lower IGF-BP2 level in the CTRL group compared to the BF group (p < 0.01) and a higher IGF-BP3 level in the mLP group compared to the BF group (p = 0.03). There were no significant differences in glucose, leptin, and IGF-1 between the three feeding groups. We found specific associations of all early-life metabolic and hormonal blood parameters with long-term growth and body composition except for IGF-1. Conclusions: Reducing protein intake by 20% did not result in a different metabolic profile in formula-fed infants at 4 months of age. Formula-fed infants had a lower insulin sensitivity compared to breast-fed infants. We found associations between all metabolic and hormonal markers (except for IGF-1) determined at age 4 months and growth and body composition up to two years of age.


1998 ◽  
Vol 275 (2) ◽  
pp. E310-E320 ◽  
Author(s):  
Anders H. Forslund ◽  
Leif Hambraeus ◽  
Roger M. Olsson ◽  
Antoine E. El-Khoury ◽  
Yong-Ming Yu ◽  
...  

In healthy adult men adapted to a diet/exercise regimen for 6 days, the effects of small, frequent meals supplying daily protein intakes of 1 ( n = 8) or 2.5 g ⋅ kg−1 ⋅ day−1( n = 6) on leucine oxidation, urea production, and whole body protein synthesis (PS) and degradation (PD) have been compared with the use of a 24-h continuous intravenous [13C]leucine and [15N,15N]urea infusion protocol. Two 90-min periods of exercise (∼50% maximal O2 consumption) were included during the fasting and the fed periods of the 24-h day. Subjects were determined to be at approximate energy, nitrogen, and leucine balances on both diets. Increased protein intake raised the urea production rate; the absolute rate of urea hydrolysis was the same on both diets. When the first-pass splanchnic uptake of leucine was taken to be 25% of intake, PS was stimulated by feeding (after an overnight fast) at both protein intake levels ( P < 0.05 and P < 0.01), whereas PD declined significantly ( P < 0.01) at both protein levels. Protein gain at a high protein intake appears to be the result of both a stimulation of PS and a marked decline in PD, whereas at a less generous intake, the gain appears to be a result of a fall in PD with a less evident change in PS. Exercise moderately decreased PS during and/or immediately after exercise at each protein level, and there was a postexercise-induced increase ( P < 0.01) in PD, which was more dramatic when feeding was at the higher protein intake level.


1997 ◽  
Vol 77 (6) ◽  
pp. 853-862 ◽  
Author(s):  
Bronwyn Diffey ◽  
Leonard S. Piers ◽  
Mario J. Soares ◽  
Kerin O'dea

AbstractThe use of oral contraceptive agents by women may be a factor that contributes to the observed inter-individual variability in the BMR. We, therefore, measured the BMR, body build and composition in two groups of young women and also assessed their self-reported level of physical activity. One group had been using oral contraceptive agents for a period of 6 months or more (OCA, n 24), while the other group had never used oral contraceptives (NOCA, n 22). There were no significant differences in age, body build or composition. The absolute BMR in the two groups were not significantly different when compared using an unpaired t test (OCA: 5841 (SD 471) v. NOCA: 5633 (SD 615)kJ/d). However, using an analysis of covariance, with either body weight or a combination of fat and fat free mass as covariates, the OCA group had a BMR almost 5% higher than that of the NOCA group (OCA: 5871 v. NOCA: 5601 kJ/d; P=0·002). When those subjects with high self-reported levels of physical activity were excluded, the difference in BMR between the two groups persisted (P = 0·001). An ANOVA of oral contraceptives use and phase of menstrual cycle showed significant differences in BMR with use of oral contraceptives (P=0·004) but no difference in BMR between phases of the menstrual cycle. In conclusion, the ose of oral contraceptive agents deserves consideration when conducting and analysing data from studies on energy metabolism in young women, as it results in a significantly higher BMR.


Author(s):  
Shehnaz Shaikh

Introduction: Menstrual cycle or menstruation involved discharge of sanguinous fluid and a sloughing of uterine wall. In women menstruation occurs at regular intervals on an average of 28 days, although most women gave a history of regular intervals of 28 to 30 days. About 10% -15% of women showed cycle at the precise 28 ± 2 days intervals when menstrual calendar was utilized. Normally in young women in different phases of ovarian cycles the plasma levels of estrogen vary. Ovulation occurs in the first 12-13th day of menstrual cycle, which is termed estrogen surge and second occurs in mid-luteal phase. During mid cycle or follicular phase of menstrual cycle the plasma concentration of progesterone is very low about 0.9 ng/mL. its level starts rising owing to secretion from the granulose cells. During luteal phase progesterone level reaches its peak value of 18 ng/mL and its level fall to a minimum value toward the end of the cycle. Estrogen affects local and systemic vasodilation. The menstrual cycle envelops two fundamental stages, the follicular stage (FP) and the luteal stage (LP). The follicular stage can part advance into two substages; the early FP, which is characterised with moo concentrations of both the key hormones estrogen and progesterone; and the mid FP where estrogen is tall autonomously from progesterone. The LP is epitomized by tall concentration of both estrogen and progesterone. These two fundamental stages are isolated by a soak surge in luteinizing hormone activating ovulation. These recurrent changes are said to be frequency unsurprising while long time. Aim: The main aim of this study is to evaluate the Cardiorespiratory functions changes during different Phases of Menstrual Cycle.   Material and methods: In this study, 20 with normal weight, 20 with obese and 20 with overage were included and taken them as a sample size. In this study all the young women those were recruited as a sample size are unmarried, undergraduate female student with the between the age group of 18-22years, having regular 28+6 days menstrual cycle for at least last 6months prior to this study. For the collection of data all the participants were instructed to attend the physiology lab department during each of three different phases. Day-2 during menstrual phase, Day-7, during follicular phase and Day-22 during luteal phase and the following parameters were recorded as Anthropometric measurements, measuring of pulse rate and blood pressure and cardiac efficiency test. Result: In general, work out proficiency changed essentially amid the distinctive stages of the menstrual cycle with the most elevated amid luteal stage and least amid menstrualo stage. There was no critical contrast in impact test amid menstrual stage, follicular stage and luteal stage of menstrual cycle among three bunches of people. Conclusion: We have watched noteworthy increment in cardiac and respiratory proficiency within the luteal stage of the menstrual cycle in ordinary weight people. Lower wellness levels were watched in overweight and stout females. In this manner hone of customary work out and admissions of solid slim down which offer assistance in lessening the weight and in turn the BMI will offer assistance in improving the physical wellness of the people. Keywords: Cardiorespiratory, Menstrual cycle, expiratory blast test


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tomomi Yamazaki ◽  
Sae Maruyama ◽  
Yuki Sato ◽  
Yukako Suzuki ◽  
Sohei Shimizu ◽  
...  

Abstract Background The purpose of the present study was to examine the relationship between ankle joint laxity and general joint laxity (GJL) in relation to the menstrual cycle, which was divided into four phases based on basal body temperature and ovulation, assessed using an ovulation kit. Methods Participants were 14 female college students (21–22 years) with normal menstrual cycles (cis gender). Anterior drawer stress to a magnitude of 120 N was applied for all participants. Anterior talofibular ligament (ATFL) length was measured as the linear distance (mm) between its points of attachment on the lateral malleolus and talus using ultrasonography. Data on ATFL length from each subject were used to calculate each subject’s normalized length change with anterior drawer stress (AD%). The University of Tokyo method was used for evaluation of GJL. AD% and GJL were measured once in each menstrual phase. Results There was no statistically significant difference between AD% in each phase. GJL score was significantly higher in the ovulation and luteal phases compared with the early follicular phase. AD% and GJL showed a positive correlation with each other in the ovulation phase. Conclusions Although it is unclear whether estrogen receptors are present in the ATFL, the present study suggests that women with high GJL scores might be more sensitive to the effects of estrogen, resulting in ATFL length change in the ovulation phase.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alenka Mavri ◽  
Nina Vene ◽  
Mojca Božič-Mijovski ◽  
Marko Miklič ◽  
Lisbeth Söderblom ◽  
...  

AbstractIn some clinical situations, measurements of anticoagulant effect of apixaban may be needed. We investigated the inter- and intra-individual apixaban variability in patients with atrial fibrillation and correlated these results with clinical outcome. We included 62 patients receiving either 5 mg (A5, n = 32) or 2.5 mg (A2.5, n = 30) apixaban twice-daily. We collected three trough and three peak blood samples 6–8 weeks apart. Apixaban concentration was measured by liquid chromatography-tandem mass-spectrometry (LC–MS/MS) and by anti-Xa. Patients on A2.5 were older, had lower creatinine clearance, higher CHA2DS2VASc (4.7 ± 1.0 vs. 3.4 ± 1.7) and lower trough (85 ± 39 vs. 117 ± 53 ng/mL) and peak (170 ± 56 vs. 256 ± 91 ng/mL) apixaban concentrations than patients on A5 (all p < 0.01). In patients on A5, LC–MS/MS showed a significant difference between through levels and between peak levels (p < 0.01). During apixaban treatment, 21 patients suffered bleeding (2 major). There was no association between bleeding and apixaban concentrations or variability. Four patients who suffered thromboembolic event had lower peak apixaban concentrations than patients without it (159 ± 13 vs. 238 ± 88 ng/mL, p = 0.05). We concluded, that there was a significant intra- and inter-individual variability in apixaban trough and peak concentrations. Neither variability nor apixaban concentrations were associated with clinical outcomes.


Zygote ◽  
2020 ◽  
pp. 1-3
Author(s):  
Burcu Ozbakir ◽  
Pinar Tulay

Summary Alcohol consumption has long been shown to affect both fetal health and pregnancy. In this study, antral follicle count, maturation level of oocytes including morphological assessment and number of metaphase I (MI), metaphase II (MII) and germinal vesicle (GV) stage oocytes obtained from young women (age < 30 years old) with or without alcohol consumption were investigated. In total, 20 healthy women who were social drinkers and 36 healthy women who do not consume alcohol were involved in this study. Women in both study and control groups were undergoing controlled ovarian stimulation. The antral follicle count and the number and quality of the oocytes retrieved were evaluated and recorded. In total, 635 antral follicles, 1098 follicles and 1014 oocytes with 820 MII, 72 MI and 78 GV stage oocytes were collected from the social drinkers. In the control group, 628 antral follicles, 1136 follicles and 1085 oocytes with 838 MII, 93 MI and 102 GV stage oocytes were evaluated. The results of this study showed that the antral follicle count was very similar in both groups. The number of oocytes and MII stage oocytes was slightly higher in the control group, although it was not a significant difference. This study showed that although the consumption of alcohol may have adverse effects post-implantation, it may not have a solid effect during oogenesis in young women. The results of this study are especially important in clinical settings as some women who are social drinkers undergo in vitro fertilization treatments.


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