Larger splenic emptying correlate with slower EPOC kinetics in healthy men and women during supine cycling.

PURPOSE: The present study investigated whether larger splenic emptying augments faster excess post-exercise O2 consumption (EPOC) following aerobic exercise cessation. METHODS: Fifteen healthy participants (age 24 ± 4, 47% women) completed 3 laboratory visits at least 48-h apart. After obtaining medical clearance and familiarizing themselves with the test, they performed a ramp-incremental test in the supine position until task failure. At their final visit, they completed three step-transition tests from 20 W to a moderate-intensity power output (PO), equivalent to [Formula: see text]O2 at 90% gas exchange threshold, where data on metabolic, cardiovascular, and splenic responses were recorded simultaneously. After step-transition test cessation, EPOCfast was recorded, and the first 10 min of the recovery period was used for further analysis. Blood samples were collected before and immediately after the end of exercise. RESULTS: In response to moderate-intensity supine cycling ([Formula: see text]O2 = ~ 2.1 L·min-1), a decrease in spleen volume of ~ 35% (p = 0.001) was observed, resulting in a transient increase in red cell count of ~ 3-4% (p = 0.001) in mixed venous blood. In parallel, mean blood pressure, heart rate, and stroke volume increased by 30-100%, respectively. During recovery, mean τ[Formula: see text]O2 was 45 ± 18 s, the amplitude was 2.4 ± 0.5 L·min-1, and EPOCfast was 1.69 L·O2. Significant correlations were observed between the percent change in spleen volume and (i) EPOCfast (r = - 0.657, p = 0.008) and (ii) τ[Formula: see text]O2 (r = - 0.619, p = 0.008), but not between the change in spleen volume and (iii) [Formula: see text]O2 peak (r = 0.435, p = 0.105). CONCLUSION: Apparently, during supine cycling, individuals with larger spleen emptying tend to have slower [Formula: see text] O2 recovery kinetics and a greater EPOCfast.

No differences in splenic emptying during on-transient supine cycling between aerobically trained and untrained participants.

PURPOSE: The role of splenic emptying in O2 transport during aerobic exercise still remains a matter of debate. Our study compared the differences in spleen volume changes between aerobically trained and untrained individuals during step-transition supine cycling exercise at moderate-intensity. We also examined the relationship between spleen volume changes, erythrocyte release, and O2 uptake parameters. METHODS: Fourteen healthy men completed all study procedures, including a detailed medical examination, supine maximal O2 uptake ([Formula: see text] max.) test, and three step-transitions from 20 W to a moderate-intensity power output, equivalent to [Formula: see text] uptake at 90% gas exchange threshold. During these step-transitions pulmonary [Formula: see text], near-infrared spectroscopy of the vastus lateralis, and cardiovascular responses were continuously measured. In parallel, minute-by-minute ultrasonic measurements of the spleen were performed. Blood samples were taken before and immediately after step-transition cycling. RESULTS: On average, [Formula: see text] max. was 10 mL kg min-1 (p = 0.001) higher in trained compared to their aerobically untrained peers. In response to supine step-transition cycling, the splenic volume was significantly reduced, and the largest reduction (~ 106 to 115 mL, ~ 38%, p = 0.001) was similar in both aerobically trained and untrained individuals. Erythrocyte concentration and platelet count transiently increased after exercise cessation, with no differences observed between groups. However, the vastus lateralis deoxygenation amplitude was 30% (p = 0.001) greater in trained compared to untrained individuals. No associations existed between: (i) spleen volumes at rest (ii) spleen volume changes (%), (iii) resting hematocrit and oxygen uptake parameters. CONCLUSION: Greater splenic emptying and subsequent erythrocyte release do not lead to a slower [Formula: see text], regardless of individual [Formula: see text] max. readings.

Calculation of optimal gestation weight gain in pre-pregnancy underweight women due to body mass index change in relation to mother's height.

BACKGROUND: Optimal gestational weight gain has not yet been clearly defined and remains one of the most controversial issues in modern perinatology. The role of optimal weight gain during pregnancy is critical, as it has a strong effect on perinatal outcomes. PURPOSE: In this study, gestational body mass index (BMI) change, accounting for maternal height, was investigated as a new criterion for gestational weight gain determination, in the context of fetal growth assessment. We had focused on underweight women only, and aimed to assess whether the Institute of Medicine (IOM) guidelines could be considered acceptable or additional corrections are required in this subgroup of women. METHODS: The study included 1205 pre-pregnancy underweight mothers and their neonates. Only mothers with singleton term pregnancies (37th-42nd week of gestation) with pre-gestational BMI < 18.5 kg/m2 were enrolled. RESULTS: The share of small for gestational age (SGA) infants in the study population was 16.2 %. Our results showed the minimal recommended gestational weight gain of 12-14 kg and BMI change of 4-5 kg/m2 to be associated with a lower prevalence of SGA newborns. Based on our results, the recommended upper limit of gestational mass change could definitely be substantially higher. CONCLUSION: Optimal weight gain in underweight women could be estimated in the very beginning of pregnancy as recommended BMI change, but recalculated in kilograms according to body height, which modulates the numerical calculation of BMI. Our proposal presents a further step forward towards individualized approach for each pregnant woman.

Spleen emptying does not correlate with faster oxygen kinetics during a step-transition supine cycling.

This manuscript quantified spleen volume changes and examined the relationship between those changes and oxygen uptake kinetics during supine cycling. Ten volunteers (age = 22 ± 3), completed 3 step transitions from 20 W to their power output at 90% gas exchange threshold. Ultrasonic measurements of the spleen were performed each minute. The largest spleen volume reduction was 105 mL (p = 0.001). No associations existed between i) spleen volumes at rest; and ii) spleen volume changes (%) and tau pulmonary oxygen uptake (τV̇O2p). Larger resting spleen volume and greater emptying do not correlate with a faster τV̇O2p. Novelty: Greater splenic contractions do not augment τV̇O2p, irrespective of spleen emptying and subsequent erythrocyte release.

Vitamin B12 Supplementation in Addition to Folic Acid and Iron Improves Hematological and Biochemical Markers in Pregnancy: A Randomized Controlled Trial.

Vitamin B12 plays an important role in cell division and is of vital importance during pregnancy. Iron and B12 deficiency increase the risk of neonatal morbidity and the outcome of the overall pregnancy. The aim of our study was to analyze whether the use of vitamin B12, with standard supplements of folic acid and iron among nonanemic pregnant women, will result in improvements of hemogram parameters in terms of hematological and biochemical markers. Study participants were 200 healthy pregnant women, randomized into an intervention group and a control group, recruited from gynecological primary care practices in Split, Croatia. In addition to standard supplementation (350 mg/day ferrous iron, 5 mg folic acid), participants in the intervention group were given 5 µg of vitamin B12 each morning for 100 days. Both biochemical and hematological measurings were conducted in two intervals: 8th-10th week of gestation and then again in the 34th-36th week of gestation. Participants in the control group were given only standard-of-care iron and folic acid supplementation. Significantly lower values of haptoglobin postintervention, compared with baseline, were found only in the intervention group; for erythrocytes, significantly lower values postintervention were found only in the control group. For parameter hematocrit, we found decreased values postintervention, compared with baseline, in both intervention and control group; however, this decrease was within the reference range for the control group, whereas it was above the reference range for the intervention group. The results of this study indicated that intervention with vitamin B12 in pregnancy reduces possibilities of the onset of anemia, but within reference range.