Experience and Utility of the Protocol Kidney Biopsy in the First Year of Kidney Transplantation.

BACKGROUND: Protocol kidney biopsy (PKB) in kidney transplant is a useful tool for graft monitoring because the subclinical detection of histologic lesions helps to modulate immunosuppression. We analyze our experience. METHODS: We performed a descriptive study that analyzed the PKB results at the fourth to sixth month and the first year post transplant of patients with kidney transplant followed in our hospital between January 2015 and June 2021. RESULTS: A total of 100 patients and 134 biopsy results were included, of which 71 were obtained between the fourth and sixth month and 63 at the first year. The mean age was 57.8 years, and 66% were men. Unknown etiology was the most common underlying kidney disease (31%), followed by diabetes mellitus (15%) and polycystic kidney disease (14%). A total of 80% had panel-reactive antibody < 50%. Induction therapy consisted of thymoglobulin (51%) and basiliximab (49%), and maintenance therapy consisted of corticosteroids and tacrolimus (100%), mycophenolate mofetil (82%), and mammalian target of rapamycin inhibitor (18%). Of the total of the PKB results (n = 134), 19 episodes of subclinical rejection (14%) and 10 with borderline changes (7.4%) were observed. Regarding other findings, there were cases of nephrocalcinosis (4.4%), immunoglobulin A nephropathy (2.2%), and BK nephropathy (1.5%). The PKB brought about a change in the therapeutic attitude in 45 cases (33%) of the total number of biopsies, the most frequent change being the administration of boluses of methylprednisolone (12.6%) and the change to mammalian target of rapamycin inhibitor (8.9%). CONCLUSIONS: In our experience, PKB is a useful tool for monitoring and evaluating histologic changes without clinical expression in the kidney graft, allowing us to adapt the treatment during the first year of kidney transplant.

Energy intake and expenditure of free-living, pregnant Colombian women in an urban setting.

BACKGROUND: This study examined the components of energy balance in poor, free-living pregnant women living in an urban setting of a developing country. OBJECTIVES: We tested the following hypotheses: 1) energy intake increases in pregnancy and is greater than when nonpregnant and nonlactating (NPNL), 2) basal metabolic rate (BMR) increases in pregnancy and the increase is positively correlated with prepregnancy fatness, and 3) energy expenditure in activity decreases in pregnancy and is lower than in NPNL women. DESIGN: Pregnant women were studied at 14.8 +/- 3.4 (n = 40), 25.0 +/- 3.2 (n = 54), and 34.9 +/- 2.4 (n = 43) wk gestation, and NPNL women at baseline (n = 114) and at 3 (n = 103) and 6 (n = 93) mo. Energy intake was measured by using estimated diet records and energy expenditure by using the flex heart rate method. Time allocation in physical activity was assessed by observation. RESULTS: In pregnant women, body weight, BMR, and energy intake increased but total daily energy expenditure (TDEE) did not change significantly. There were no significant changes in time allocation to selected activities except for lying down. In comparison with NPNL control subjects, women in late pregnancy had higher energy intakes and BMRs. Values for TDEE were not significantly different, but pregnant women expended less energy in activity and allocated more time to 2 energy-saving activities and less time to 2 energy-demanding activities. CONCLUSION: A decrease in energy expenditure in activity and changes in time allocation are important ways in which pregnant women meet the energy demands of pregnancy.

Marginal malnutrition in school-aged Colombian boys: metabolic rate and estimated daily energy expenditure.

Total daily energy expenditure (TDEE) and energy expenditure in activity (EAc) were estimated in 114 free-ranging, nutritionally normal, and undernourished boys 6-16 yr of age by measuring basal and resting metabolic rates, average daily heart rate while awake, and oxygen consumption and heart rate during exercise on a treadmill. Mean daily heart rates were in the range of exercising heart rates and gave reasonable estimates of TDEE and EAc. TDEE increased with age (p less than 0.001) and was reduced in undernourished boys (p = 0.011). Results indicate that nutritional group differences in TDEE were due to differences in body size. EAc increased with age but did not show significant differences between nutritional groups, indicating that in the marginal malnutrition of school-aged children, reduced growth and associated economy of energy expenditure in locomotion is sufficient physiological adaptation. Peer pressure in school and play activities may interfere with the protective mechanism of reduced activity.

Basal metabolic rate of Colombian children 2-16 y of age: ethnicity and nutritional status.

Measurements of basal metabolic rate (BMR) were made in 528 children 2-16 y of age living in underprivileged areas of the city of Cali, Colombia (153 control and 186 undernourished boys, 93 control and 96 undernourished girls). The data are related to BMR calculated from the equations of Schofield and to estimates of the lean body mass (LBM). The ethnic composition of the subjects was 80% mestizo (mixed European and South Amerindian ancestry), 15% black, and 5% white. The data do not show any variations due to race in these subjects. The Schofield equations overestimate the BMR of boys by approximately 6% whereas the estimation of BMR in girls is not significantly different from measured values. More than 65% of the variation in BMR of both nutritionally normal and undernourished boys and girls is explained by variation in body size as estimated by the LBM.

Energy expenditure of urban Colombian women: a comparison of patterns and total daily expenditure by the heart rate and factorial methods.

The heart rate and factorial methods of measuring both total daily energy expenditure (TDEE) and the daily pattern of energy expenditure (EE) were compared in nonpregnant, nonlactating women aged 19-43 y living in urban conditions of economic deprivation. The methods were applied on each of 2 successive days. There were no significant differences between the 2 d by either method. Women who worked at their household chores at home (n = 29) and those who also worked for remuneration (at work) in various kinds of employment (n = 23) were compared. The factorial method gave values for TDEE and for the pattern of EE that were significantly lower than those obtained by the heart rate method. This was related to lower values for EE for certain activities obtained from the literature than for values measured in these subjects. Women at work had significantly higher values for both TDEE and for the pattern of EE than did those at home. The TDEE at home by the heart rate method was 8.83 +/- 1.94 MJ/d and at work was 9.99 +/- 1.91 MJ/d (P = 0.036); this difference disappeared when adjusted for body weight or fat-free mass. Physical activity levels were 1.83 +/- 0.43 for women at home and 1.90 +/- 0.46 for women at work, which indicate moderate to heavy work. The factorial method should be used with measured EE values in the present subject population. The heart rate method can detect differences in TDEE and in the pattern of EE between women engaged in different activities and may offer an experimental approach to the study of the effects of daily variations in EE on nutritional energy intake.

Marginal malnutrition in school-aged Colombian boys: anthropometry and maturation.

Colombian reference data for weight and height were used to classify 1108 boys 6 to 16 yr old as nutritionally normal, low weight for age, and low weight for height. The normal group in upper socioeconomic urban and normal, low weight for age, low weight for height groups in lower socioeconomic urban and rural populations were studied. The achieved growth, growth velocities, skinfolds, mid-arm and head circumferences, and sexual maturation were all depressed in the nutritionally deprived groups indicating marginal malnutrition. Since normal boys exist in low socioeconomic and rural populations, normative data for economically advantaged children (national standards), on the average, may serve as desirable goals for low socioeconomic and rural populations. Different cutoff points for achieved growth might be established for marginal malnutrition using national or international reference populations. These ought to be age-related because of accumulated effect of slowed growth with age. Head circumference of school-aged children may proved a useful anthropometric tool in deciding early nutritional history.

PIP: Colombian reference data for weight and height were used to classify 1108 boys 6 to 16 years old as nutritionally normal, low weight for age, and low weight for height. The normal group in upper socioeconomic urban and normal, low weight for age, low weight for height groups in lower socioeconomic urban and rural populations were studied. The achieved growth, growth velocities, skinfolds, midarm and head circumferences, and sexual maturation were all depressed in the nutritionally deprived groups indicating marginal malnutrition. Since normal boys exist in low socioeconomic and rural populations, normative data for economically advantaged children (national standards), on the average, may serve as desirable goals for low socioeconomic and rural populations. Different cutoff points for achieved growth might be established for marginal malnutrition using national or international reference populations. These ought to be age related because of accumulated effect of slowed growth with age. Head circumference of school aged children may provide a useful anthropometric tool in deciding early nutritional history.

Marginal malnutrition in school-aged Colombian boys: body composition and maximal O2 consumption.

Do changes in body composition account for the changes in O2 consumption during maximal exercise (VO2max) in nutritionally deprived boys? School age urban and rural boys with no deficits (N) or with significant deficits (W-H) in weight for age and for height were studied. Percentage lean body mass was higher in W-H than in N boys. By contrast percentage intracellular water, the creatinine excretion coefficient and percentage arm muscle mass were not higher in W-H boys. Thus nutritional compromise decreased more the cellular than the support tissues of the body. VO2max per unit body weight was higher in W-H than in N boys. In the rural group, this was accounted for by the higher percentage lean body mass in W-H boys. In the urban group, VO2max/lean body mass was also higher in most W-H boys. Thus W-H urban boys had higher levels of aerobic training than N urban boys, reflecting perhaps a relative increase in daily physical activity as the same tasks have to be performed with less muscle by W-H boys.

Marginal malnutrition in school-aged Colombian boys: efficiency of treadmill walking in submaximal exercise.

Measurements of oxygen consumption (VO2) were made during submaximal treadmill exercise (3.5 mph) in 658 boys 6 to 16 yr of age classified as nutritionally normal, low weight for age, and low weight for height. Gross efficiency (at 15% grade) increased with age and was significantly lower in low weight for age and height boys than in normal children but delta efficiency showed no statistically significant differences between nutritional groups. It is concluded that marginal malnutrition has no effect on the efficiency of submaximal work during treadmill walking.

Body composition of Colombian women.

Measurements of anthropometry and total body water (TBW) were made in 99 women 19-44 y of age living in socioeconomically deprived circumstances in Cali, Colombia. TBW was measured by dilution of deuterium oxide. An empirical equation for estimating lean body mass (LBM) was derived and applied satisfactorily to an independent study group. Comparisons were also made with body-composition values obtained by the Durnin and Womersley equations and an equation derived from rural women living in Guatemala. Neither set of equations was suitable for use with the Colombian subjects because both significantly overestimated LBM and therefore underestimated body fat. Lower values of standing height in older women suggest that they may have been subjected to more severe undernutrition during their growth than the younger subjects. When compared with a group of US women, Colombian subjects were less physically fit and had greater subcutaneous-fat deposits, which were distributed over the trunk and limbs, whereas body mass indexes and waist-hip ratios were not significantly different.

Marginal malnutrition in school-aged Colombian boys: functional consequences in maximum exercise.

The maximum treadmill oxygen consumption was measured in 1013 boys, 6 to 16 yr of age classified as nutritionally normal, low weight for age and low weight for height in upper socioeconomic urban and lower socioeconomic urban and rural groups. The marginally malnourished children (low weight for age and height) in both lower socioeconomic urban and rural groups had significantly depressed maximum treadmill oxygen consumption (85%) compared to normal boys, associated with smaller body weights. It is suggested that the reduced body size and maximum treadmill oxygen consumption resulting from marginal malnutrition during growth will have a detrimental effect on work capacity and productivity of these children when they become engaged in heavy physical work as adults. There was no statistically significant correlation between blood Hb concentration (approximately 10 to 15 g x dl-1) and aerobic capacity.

Variation of the basal metabolic rate and dietary energy intake of Colombian women during 1 y.

Anthropometry, basal and resting metabolic rates (BMR and RMR), and dietary energy intake were measured on five occasions approximately 3 mo apart for 1 y in 21 nonpregnant, non-lactating women 20-42 y of age living under deprived economic conditions in Cali, Colombia. There was a significant increase in body weight (1-1.5 kg) because of increased body fat during the last two rounds of measurement. BMR was elevated in the first round but fell to stable values that did not vary significantly from 3 to 12 mo. The intraindividual CV of BMR was 8.3% whereas the intraindividual CV of dietary energy intake was 17%. Measured BMR was closely related to the BMR estimates provided by the empirical equations of Schofield, but significantly higher than estimates from the equations of Henry and Rees. RMR-BMR ratios were very close to those published by FAO/WHO/UNU. Autocorrelation analysis of BMR showed weak ability to predict subsequent variation of BMR over time and is consistent with random variation of the data.

Energy expenditure from minute-by-minute heart-rate recording: comparison with indirect calorimetry.

Total daily energy expenditure (TDEE) and energy expended in activity (EAC) were estimated by the minute-by-minute heart-rate method in 22 (16 men, 6 women) individually calibrated subjects and compared with values obtained by whole-body indirect calorimetry. Subjects followed four activity protocols during the 22 h in the calorimeter; no exercise (n = 6) and 2 (n = 5), 4 (n = 4), and 6 (n = 6) 30-min bouts of exercise on a bicycle ergometer at varying intensities. There were no statistically significant differences between the two methods in TDEE or EAC in any of the sex or protocol groupings. The regression of TDEE by heart rate on TDEE in the calorimeter was y = 0.92x + 1.0 MJ; (r = 0.87, SEE = 0.91 MJ). The heart-rate method also follows the varying activity patterns of individuals and can be used to closely estimate the TDEE and EAC of even small (n = 4-6) groups of subjects. In the present measurements, it gave a maximum error of TDEE for individuals of +20% and -15%.

Daily pattern of %VO2max and heart rates in normal and undernourished school children.

The pattern of usage of the VO2max, expressed as %VO2max during ordinary school days, with minute-by-minute heart rate recording, was studied in 106 boys and 83 girls, 6-16 yr of age divided into three age groups (6-8, 10-12, and 14-16 yr), living under economically deprived conditions in Colombia and classified as nutritionally normal or marginally malnourished. In a 12-h period, the 12 groups of children spent, on the average, 7-10 h at less than 30% VO2max, 1.5-4 h at 30-50% VO2max, and an accumulated time of 20-60 min above 50% VO2max. The latter occurred in short bursts rather than during sustained periods. There was a statistically significant but small decrease (approximately -3%) in the average 12 h %VO2max with age but no effects of sex or nutritional status. The overall average was about 25% VO2max in all groups. The data may suggest the existence of the regulation of physical activity to some level easily sustainable for long periods. Expressing the data as 30 min averages during 5 h of school and 5 h of free-time activity allows for the possibility of seeing group differences during shorter periods of time. This may prove useful in exercise training programs and studies of effort in the workplace.

Daily energy expenditure of women by factorial and heart rate methods.

To compare the minute-by-minute heart rate (Flex-HR) reference method with the factorial method, total daily energy expenditure (TDEE) and the pattern of daily energy expenditure (EE) were measured in nonpregnant, nonlactating women 19-40 yr of age, working at their household chores (at home, N = 20) or for remuneration in various kinds of employment (at work, N = 28). The factorial method used three data sets described in the compendium of Ainsworth et al. (CMD), FAO/WHO/UNU (FAO), and James and Schofield (J&S). Measurements were repeated on three rounds separated by 3 months. The TDEE by Flex-HR method, by round, was 9.0 +/- 2.6, 8.9 +/- 1.4, and 10.3 +/- 3.4 MJ.d-1 in the women at home and 9.7 +/- 2.3, 11.4 +/- 3.2, and 11.3 +/- 3.6 MJ.d-1 in the women at work. Values using the CMD data set were not significantly different from Flex-HR in either group in any round, but FAO and J&S data sets gave significantly lower values than both of the former methods in all rounds. The same statistical results were obtained for the patterns of activity. Since the timing of activities by the observers was the same, it is concluded that the major source of error in applying the factorial method is in the values for energy expenditure assigned to the various activities and the ability of investigators to properly judge EE from available data sets.

Basal metabolic rate of normal and marginally undernourished mestizo children in Colombia.

The basal metabolic rate (BMR) was measured in mestizo children 6-16 years of age living under economically deprived conditions in Colombia. Of a total of 239 boys and 126 girls, 137 boys and 72 girls were classified as marginally malnourished. Differences in BMR by age, sex and nutritional group could be accounted for by differences in lean body mass. The Schofield equations were found to overestimate BMR significantly in the boys. However, the estimates in girls were not significantly different from measured values.

Influence of dietary intervention on artificially increased activity in marginally undernourished Colombian boys.

Studies of the pattern of daily energy expenditure (EE), total daily energy expenditure (TDEE) and energy expended in activity (EAC) have been carried out in 14 nutritionally normal and 19 marginally malnourished, free-living boys 10-12 years of age using the minute-by-minute heart rate recording technique. Measurements were made during an ordinary school day and again about 6 months later under conditions of a summer day-camp where the activity levels were artificially increased by encouragement to participate in supervised sports activities and play. The morning and afternoon activities were separated by a dietary intervention in the form of a hot meal providing approximately 3.2 MJ (760 kcal). In the morning sessions of the day-camp the undernourished boys did not keep up with the control group by increasing their EE. However, for about 2 h following the noon meal, they did increase EE to levels comparable to the control group but again reduced their EE later in the afternoon and earlier than the control subjects. The data show an inability of undernourished boys to increase their activity which is positively affected for a short period by dietary intervention.

Patterns of daily energy expenditure in normal and marginally undernourished school-aged Colombian children.

Using minute-by-minute heart rate recording, the pattern of energy expenditure (EE), total daily energy expenditure (TDEE) and energy expenditure in activity (EAC) were measured in 132 boys and 110 girls 6-8, 10-12 and 14-16 years of age during ordinary school days. The children were living under economically deprived conditions in Colombia; 70 boys and 59 girls were classified as having marginal malnutrition of sufficient degree to retard growth and sexual maturation. EE, TDEE and EAC increased with age, were in general less in undernourished than control subjects and less in girls than in boys. The age and nutritional group effects were ascribable to differences in lean body mass (LBM). However, the reduced activity in girls was greater than could be accounted for by differences in LBM and are probably the result of cultural pressures. Thus, at the levels of normal activity encountered during school days, the reduced energy expenditure found in undernourished children can be accounted for by differences in body size.

Energy expenditure/basal metabolic rate ratios in normal and marginally undernourished Colombian children 6-16 years of age.

Measurements of basal (BMR) and resting (RMR) metabolic rates, maintenance (MEE) and total daily energy expenditures (TDEE) have been made in Colombian children 6-16 years of age classified as nutritionally normal (boys, n = 129; girls, n = 72) and marginally undernourished (boys, n = 171; girls, n = 74). TDEE/BMR ratios were calculated for comparison with those suggested by FAO/WHO/UNU (1985) and to provide data for children less than 10 years of age. TDEE was measured in free-living, individually calibrated subjects by the heart-rate method. TDEE/BMR increased significantly with age in boys from 1.60 to 1.84 in control subjects and 1.46 to 1.92 in undernourished boys. There was no significant increase with age in the girls. There were no statistically significant differences between nutritional groups but girls had significantly lower values than boys. There was a greater rate of increase in TDEE than BMR with age and girls spent more time in light activities and less in high level activities than boys.

Energy intake and expenditure of free-living, lactating Colombian women in an urban setting.

OBJECTIVES: To examine the components of energy balance during lactation in a population of economically disadvantaged women in an urban developing country setting in order to better understand the metabolic response to lactation. DESIGN: Cross-sectional comparison of lactating (LACT) and non-pregnant non-lactating (NPNL) women. Body size and composition were assessed via anthropometry, energy intake was measured using estimated diet records and energy expenditure using indirect calorimetry and the Flex-Heart Rate method. SETTING: Low-income neighborhoods of Cali, Colombia. SUBJECTS: Lactating women (n=15) studied at 2.4+/-0.8, 5.5+/-0.8 and 8.9+/-1.2 months postpartum, and NPNL women (n=48) studied in three measurement rounds at 0, 3.5+/-0.6 and 7.1+/-1.0 months. RESULTS: There were no significant differences between LACT and NPNL women in anthropometric dimensions, but LACT women showed decreases in waist-hip ratio, lean body mass and increases in mid-arm circumference and percentage body fat with time. Energy intake was higher in LACT women (P=0.04), but there were no significant between-group differences in energy expenditure variables. CONCLUSION: This group of women met the cost of lactation principally via increased energy intake.

Increased muscular efficiency during lactation in Colombian women.

OBJECTIVE: To determine the muscular efficiency of lactating women and compare it to that of nonpregnant, nonlactating (NPNL) women. DESIGN: The study was retrospective. The subjects were selected randomly in the two groups and studied on three occasions (rounds) separated by approximately three months. SUBJECTS: There were 109, 101, and 80 NPNL women and 45, 31 and 16 lactating women in rounds 1, 2 and 3 respectively, 19-43 y of age, living under economically deprived conditions in Cali, Colombia, who participated in the study. METHODS: Muscular efficiency was measured as delta efficiency on a cycle ergometer. RESULTS: Muscular efficiency was significantly higher in lactating women in all three rounds compared to NPNL women. In six women it was possible to measure efficiency at variable times prior to their pregnancies, and again during lactation about three months post partum. There was a statistically significant (P = 0.03) increase in muscular efficiency during lactation. CONCLUSION: Lactation results in about a 5% increase in muscular efficiency which may contribute to the adaptation of the mother to the increased energy demands associated with lactation.

PIP: The muscular efficiency of low-income lactating women living in Cali, Colombia, was compared to that of nonpregnant, nonlactating women from the same neighborhoods in a retrospective study that involved 3 rounds separated by about 3 months. Rounds 1, 2, and 3 (occurring at an average of 2.4, 5.3, and 8.6 months postpartum) included 109, 101, and 80 nonpregnant, nonlactating women, respectively, and 45, 31, and 16 lactating women, respectively. Muscular efficiency, measured as delta efficiency on a cycle ergometer, was significantly higher among lactating than nonlactating, nonpregnant women in all 3 rounds. In the 6 women in whom it was possible to measure muscular efficiency at variable times prior to their pregnancy as well as at 3 months postpartum, there was a statistically significant increase in muscular efficiency during lactation. Overall, lactation resulted in about a 5% increase in muscular efficiency. This phenomenon may contribute to the adaptation of the mother to the increased energy demands associated with breast feeding.