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Biomedical subjects

G B Spurr

Publications and source records attributed to G B Spurr.

53 records · Page 3Linked to original sources
PubMed1979

Body composition during nutritional repletion of severely undernourished men.

Body composition was studied in severely undernourished adult male inhabitants of a rural area of Colombia to evaluate the extent and the time course of the changes occurring upon nutritional repletion. During a 45-day basal period on a low (26g/day) protein diet containing adequate calories, body fat depots increased significantly (mean +/- SD = +3.02 +/- 2.9 kg), and there was a significant decrease in cell hydration from 81.8 to 76.4% (-5.4 +/- 9.1%). Upon protein repletion (100 g/day), cell hydration decreased significantly to 71.4%, while body cell mass increased markedly (9.0 +/- 1.1 kg). During protein repletion, muscle cell mass increased significantly (+5.5 +/- 0.6 kg) and rapidly, while the increase in nonmuscle cells (+3.5 +/- 3.8 kg) and specifically in red cell mass lagged behind. With repletion, the changes in the absolute values for plasma volume (+0.4 +/- 0.13 liters) were significant, but those in extracellular fluid volume (-0.7 +/- 1.9 liters) were not. Thus, the major compositional changes observed occurred in the body fat and the body cell mass components; these occurred independently of each other.

Adipose Tissue↗
PubMed1978

Body composition in chronic undernutrition.

Anthropometric (height, weight, and skinfolds), biochemical (serum proteins, albumin, and cholesterol), metabolic (nitrogen balance and creatinine excretion), hematological (plasma volume, hemoglobin, hematocrit, bone marrow hemosiderin, percent transferrin saturation, vitamin B12, and folic acid) variables and body water compartments (total and extracellular) have been measured in 49 adult male subjects who exhibited a wide range of nutritional states from normal to severely undernourished. Changes in body composition associated with moderate degrees of nutritional compromise were related principally to decreases in body cell mass (-15%). Body fat was normal. With severe nutritional involvement, both fat depots (-29%) and body cell mass (-29%) were significantly diminished. Muscle cell mass was more affected than other cells in the body (-41%). These data could indicate that in the group with moderate compromise, energy reserves (and hence energy balance) were maintained but dietary protein deficiencies were not compensated for. Both calorie and protein deficiencies were evident in the subjects with severe undernutrition. Multiple regression equations (r greater than 0.8) were developed that allow prediction of muscle cell mass, fat-free weight, and body cell mass from simple anthropometry and serum albumin levels. Decreases in serum albumin concentration were best related to deficits in muscle mass (r = 0.77).

Adolescent↗
PubMed1978

Aerobic work capacity in chronically undernourished adult males.

Maximal O2 consumption (VO2max) and maximal endurance time at 80% Vo2max (T80) were determined in 49 subjects with varying degrees of nutritional compromise. Vo2max was lover by 21% and 52% in subjects with moderate and severe undernutrition, respectively, when compared to men with mild nutritional compromise. Most (80%) of the change in Vo2max could be related to the estimated differences in muscle cell mass (MCM). A significant reduction (-18%) in the Vo2max per unit of MCM was found in the severely undernourished subjects, indicating basic physiological changes. Total body hemoglobin showed the highest correlation with Vo2max (r = 0.709) and at constant MCM (partial r = 0.796). A multiple regression equation was derived to estimate the Vo2max of populations on the basis of simple anthropometry and blood hemoglobin levels. T80 (93-103 min) and estimated maximum sustained 8-h percent effort (32%) in mild, intermediate, or severe undernutrition were not significantly different; by contrast, endurance at a given absolute work load was markedly lower in severe undernutrition (8 vs. 1.5 h) due presumably to the difference in Vo2max.

Adipose Tissue↗
PubMed1977

Energy expenditure, productivity, and physical work capacity of sugarcane loaders.

VO2, E and heart rates (fH) were measured in 28 Colombian sugarcane loaders while loading cane and in the laboratory during a VO2max test. Productivity (metric tons-day-1) of the workers was also obtained. During work, VO2 was 1.251-min-1, VE 38.81 min-1, and fH 120 beats-min-1. The subjects worked at 42% of VO2max (6.3 +/- 1.0 kcal-min-1) during the field measurement periods. Energy expenditure was estimated to average 3,281 kcal-24 hr-1. Productivity was higher in men with lower fat content, resting fH and fH at VO2 = 1.25 1-min-1, indicating a positive relationship between productivity and physical fitness. Productivity was not related to age but, since VO2max decreased with age, the relative effort required to maintain productivity increased in the older workers. Efficiency (kg cane loaded-1 VO2-1) and estimated sustained effort (percent VO2max) were not significantly correlated with productivity in this type of discontinuous, moderate work.

Age Factors↗
PubMed1977

Productivity and maximal oxygen consumption in sugar cane cutters.

Vo2max and daily productivity (metric tons/day) have been measured in 46 sugar cane cutters 18 to 34 years of age. A multiple regression analysis demonstrated that productivity was simultaneously related to VO2max, height and body fat (r=0.685;P less than 0.001). The multiple regression equation was: productivity (tons/day)=0.81 VO2max-0.14 percent fat +0.03 height -1.96. The data indicate that productivity is affected indirectly by nutritional status through the influence of the latter on height, fat content and VO2max. The decrease in VO2max that occurs with age was similar to that reported in the literature. Evidence is presented that, as the worker ages, a higher percent VO2max has to be utilized to maintain productivity.

Adolescent↗
PubMed1977

Efficiency and daily work effort in sugar cane cutters.

Productivity (metric tons (tonnes)/day), efficiency (kg cane cut/litre Vo2), and effort (percent Vo2 max sustained during an 8-hour workday) have been measured in 54 Colombian sugar cane cutters. In workers who sustained less than 40% Vo2 max during the workday, the effort expended was related to productivity (4 = 0-71) but efficiency and productivity were not significantly correlated. In 16 workers sustaining a greater than 40% Vo2 max during the workday, productivity and effort were not related and efficiency was significantly reduced. Subjects using less than 40% Vo2 max were divided into good, average and poor producers and compared with the men with low efficiencies. In general, these inefficient men had the anthropometric and physical fitness characteristics of low productivity workers (smaller stature, weight and Vo2 max). However, the frequency of good, average, and poor cutters in the inefficient group did not differ from that of the men expending less than 40% of their maximum effort nor was their average productivity different. No obvious reasons for the differences in efficiency and effort of these men were found.

Adult↗
PubMed1976

The aerobic power of several groups of laborers in Colombia and the United States.

Physiological responses to exercise and anthropometry were measured in several groups of physical laborers. The groups included Colombian sugar cane cutters, sugar cane loaders and general farm laborers. In addition, migrant workers and civil service laborers from the United States were studied. The Colombian populations were generally shorter, weighed less and had less body fat than the United States group. The nutritional state of the Colombian groups, as measured by the hematocrit, hemoglobin, serum albumin and total blood protein, appeared normal. The aerobic power of the Colombia populations was significantly larger than the United States groups. The larger aerobic power of the Colombian groups is probably related to greater physical fitness associated with the physical demands of their occupations.

Adult↗
PubMed1975

Energy expenditure cutting supercane.

VO2 VE, and heart rates (fH) were measured in 61 Colombian sugarcane cutters while harvesting cane in the AM and PM and in the laboratory during a VO2max test. Productivity and sweat rates were also measured in the field. The subjects had an estimated dietary intake of 2,970 kcal/day, which was lower than calculated daily energy expenditure. During the work measurements the VO2 was 1.5 1/min, VE 48 1/min, and fH 135 beats/min; there were no differences between AM and PM values. The subjects sustained about 35% of VO2max during the 8 h workday, but worked at 57% of VO2max during the tests. Measured energy cost was 7.4 +/- 1.5 kcal/min during the workday. Sweat rates were higher PM than AM (5 KG/8 h day). Grouping of the men according to productivity demonstrated that taller, heavier men were better producers and had lower calculated heart rates at VO2 1.51/min. Efficiency of cane cutting was higher (9%) PM.

Adult↗
PubMedDate not supplied

Anthropometric characteristics of pregnant women in Cali, Colombia and relationship to birth weight.

Anthropometric dimensions were collected from 46 pregnant women living in Cali, Colombia to gain a better understanding of how poor, urban women deal with the demands of pregnancy and to identify relationships between maternal characteristics and infant birth weight. Height, weight, skinfold thicknesses (subscapular, suprailiac, thigh, calf, and triceps), and circumferences (hip, thigh, calf, and mid-upper arm) were measured on all women. Infant measurements were weight and length. The women were measured in the second and third trimesters, and a subsample (n = 16) was measured twice in the third trimester. Mean birth weight was 3,137.6 +/- 488.5 g (n = 44), and mean length was 49.8 +/- 3.0 cm. All but three of the infants were full-term, and the incidence of low birth weight (LBW) was 9%. The 46 women showed a significant increase in weight (P < 0.001); subscapular, suprailiac, and mid-thigh skinfold thicknesses (P < or = 0.01) and in hip, thigh, and calf circumferences (P < or = 0.01) between trimesters 2 and 3. Women who gave birth to both normal birth weight (NBW) and LBW infants showed significant increases in weight (P < 0.001 and P = 0.02, respectively), but only women who had NBW infants showed significant increases in the suprailiac skinfold and hip circumference (P < 0.001). In the third trimester, attained weight, skinfold thicknesses, and circumferences tended to be greater in women who had NBW infants. In general, this group of women gained less weight and had a greater incidence of LBW infants compared with women in developed countries, but changes in skinfold thicknesses over the course of pregnancy were similar compared with other studies.

Adult↗
PubMedDate not supplied

Physical activity of poor urban women in Cali, Colombia: a comparison of working and not working women.

We have previously presented evidence that the physical activity level (PAL) and total energy expenditure (per kg body weight) of poor urban women who "work" (engage in income-earning activities) is similar to those who do not "work" (but do tend to household and childcare responsibilities) (Spurr et al. [1996] Am J Clin Nutr 63:870-878; [1997] Med Sci Sports Exerc 29:1255-1262). These findings were unexpected and raised questions regarding the actual types of activities engaged in by the two groups. In this article we address those questions by comparing the time allocation of the two groups. Time allocation during waking hours (14.2 +/- 1.1 hours/day) was recorded in minute-by-minute diaries by trained observers for two consecutive days for 52 working women and 28 not-working women. The working women were engaged in predominately informal sector economic activities, such as street vending, childcare, and domestic service, in addition to their own household and childcare responsibilities. The activities of the not-working women were largely restricted to household and childcare responsibilities. The working women tended to spend less time in resting activities and TV-watching and more time in travel and miscellaneous work activities, but other between-group differences were not significant. We conclude that the time allocation of working women is similar to that of not-working women because 1) many of the activities engaged in are the same or similar, and 2) some working women are only engaged in income-earning activities for limited time periods.

Adult↗