The multiphasic profile of free fatty acids during the intravenous glucose tolerance test is unresponsive to exogenous insulin.

As small increments in insulin concentration profoundly affect lipolysis, our goal was to describe the free fatty acid (FFA) profile during the frequently sampled intravenous glucose tolerance test (FSIGT) and determine if both endogenous and exogenous insulin influenced the FFA profile. Thirteen subjects had both a glucose-only (GO-FSIGT) and insulin-modified FSIGT (IM-FSIGT). Both protocols were of 6 hours duration. At baseline an intravenous glucose bolus (0.3 g/kg) was given. In the IM-FSIGT, insulin was infused from 20 to 25 minutes (4 mU/kg. min). Six additional subjects had both an IM-FSIGT and a normal saline study (NS-Study). For the NS-Study, normal saline solution was infused instead of glucose and insulin. Fasting glucose, insulin, FFA and epinephrine concentrations were similar for all tests. Endogenous insulin peaked at 4 +/- 1 minute in both FSIGTs. The mean calculated peak time of exogenous insulin in the IM-FSIGT was 26 +/- 1 minute. Glucose concentrations were lower and epinephrine concentrations higher in the IM-FSIGT versus GO-FSIGT. During the FSIGTs, the FFA time course revealed four distinct phases, which did not differ between protocols. In phase I (0 to 11 minutes), FFA levels remained near basal (491 +/- 183 micromol/L); in phase II (11 to 79 minutes), FFA levels declined achieving a nadir of 139 +/- 63 micromol/L; in phase III (79 to 188 minutes), FFA levels rose linearly and reattained basal levels; and in phase IV (188 to 360 minutes), FFA levels rose above basal and plateaued at 732 +/- 214 micromol/L (P <.001). In the NS-Study, FFA levels remained near baseline (388 +/- 118 mEq/L) until 180 minutes and then trended upward to 618 +/- 258 micromol/L at 360 minutes. FFA concentrations from 180 to 360 minutes did not differ in the IM-FSIGT versus NS-Study. As the 4 FFA phases did not differ between protocols, the insulin effect on FFA levels in the FSIGT can be attributed to endogenous insulin. But the similarity in FFA levels from 180 to 360 minutes in the IM-FSIGT and NS-Study suggests diurnal variation and not a dynamic related to insulin or the FSIGT protocol is responsible for the final suprabasal FFA plateau.

Obese premenopausal African-American women with normal and impaired glucose tolerance have a similar degree of insulin resistance but differ in beta-cell function.

OBJECTIVE: To determine whether insulin resistance and secretion differ in obese premenopausal African-American women with and without glucose intolerance. RESEARCH DESIGN AND METHODS: A total of 63 women underwent oral glucose tolerance tests (OGTTs). A total of 48 women underwent frequently sampled intravenous glucose tolerance tests (FSIGTs). Insulin resistance was determined from the insulin sensitivity index (S(I)) from the FSIGT. Insulin secretion during the OGTT was determined by (I(30 min) - I(0 min))/(G(30 min) - G(0 min)) and during the FSIGT by the acute insulin response to glucose (AIRg). The disposition index, the product of AIRg and S(I), was used to determine whether AIRg was adequate to compensate for insulin resistance. Statistical analyses included one-way analysis of variance with Bonferroni corrections for multiple comparisons and regression analyses. RESULTS: The women were divided into three groups: nonobese glucose tolerant (n = 32), obese glucose tolerant (n = 17), and obese glucose intolerant (n = 14). The BMI of the three groups were 24.8 +/- 2.3, 37.8 +/- 5.5, and 42.0 +/- 7.6 kg/m(2) (mean +/- SD), respectively (P < 0.0001). The ages of the three groups were 34.9 +/- 8.4, 32.1 +/- 5.0, and 41.1 +/- 6.3 years (P = 0.011). S(I) was higher in the nonobese women than in the obese glucose-tolerant women (3.99 +/- 1.44 vs. 2.66 +/- 2.14 l x mU(-1) x min(-1), P = 0.03). S(I) was similar in the obese glucose-intolerant and obese glucose-tolerant women (2.12 +/- 1.27 vs. 2.66 +/- 2.14 l x mU(-1) x min(-1), P = 0.9). OGTT showed that insulin secretion was lower in the glucose-intolerant than the obese glucose-tolerant women (1.73 +/- 1.38 vs. 3.62 +/- 2.11, P = 0.005). FSIGT showed that AIRg was not significantly lower in glucose-intolerant than in obese glucose-tolerant women (807 +/- 665 vs. 1,253 +/- 655 mU x l(-1) x min, P = 0.078). The disposition index was lower in glucose-intolerant than in obese glucose-tolerant women (1,324 +/- 1,061 vs. 2,656 +/- 1,415, P = 0.014). CONCLUSIONS: Obese premenopausal African-American women with and without glucose intolerance have a similar degree of insulin resistance but differ in insulin secretion.

Concertina effect and facial aging: nonlinear aspects of youthfulness and skeletal remodeling, and why, perhaps, infants have jowls.

The effect of aging on the orbitomaxillary region is evaluated in the present study. The observation was made that infants look like aged individuals in terms of the midface soft-tissue contours of the midface. Because preliminary work has shown that the facial skeleton remodels throughout life, this observation led to the hypothesis that infants and older individuals appear similar because they have comparable skeletal dimensions, specifically in the orbitomaxillary region. The design is a retrospective analysis of three-dimensional computed tomographic scan data. Three groups of male subjects were studied: infant, ages 1 to 12 months (n = 5); youthful, ages 15 to 24 years (n = 13); and old, ages 53 to 76 years (n = 12). Orbital and zygomaticomaxillary vertical dimensions were measured in both medial and lateral planes between fixed anatomical landmarks. Results were compared by using analysis of variance, Student-Newman-Keuls, and Student's t tests. The findings show that skeletal remodeling is such that the ratio of the maxillary height to orbital height is greatest during youth; during infancy and old age, there is a short maxilla relative to a larger orbit. This finding is significant in the medial plane from orbital rim to pyriform aperture (p < 0.05). Furthermore, there is an actual decrease in vertical maxillary height in this medial plane (p < 0.01) from youth until old age, which occurs secondary to normal skeletal remodeling in the dentate individual. The combined effect of downward expansion of the orbital shelf and the upward migration of the pyriform effectively decreases the space available to support the overlying soft tissues of the midface. An accordion-like or "concertina" effect may lead to compression or restriction of the facial soft tissues over a relatively deficient bony platform. These results highlight the importance of skeletal remodeling in determining the soft-tissue contours of the aging face. The process of skeletal remodeling may also allow for a tentative definition of facial youthfulness. Infants are born with a short maxilla relative to a large orbit, and the maxillary wall is angled posteriorly. This ratio and angle change from infancy until youth, when there is a balance between the bony skeletal support and the overlying soft-tissue envelope, i.e., the skin, facial muscles, and adipose tissue. It is when skeletal remodeling continues past this point that a disharmony occurs. Because the ratio of maxilla/orbit, and the angle of the maxillary wall, in the older person reverts toward that of an infant, the attainment of youth occurs partly in a nonlinear or multimodal manner. This work is part of an emerging concept of facial aging, which we would term an integrated model of facial aging. This model allows facial aging to be viewed as a biological "system," in which there are primary and secondary factors that interact in the process of facial aging. Additional research such as this continues to suggest the importance of bony remodeling in facial aging.

Glucose utilization in a patient with hepatoma and hypoglycemia. Assessment by a positron emission tomography.

Tumor glucose use in patients with non-islet-cell tumors has been difficult to measure, particularly in hepatoma, because of hepatic involvement by neoplasm. We studied a patient with nonhepatic recurrence of hepatoma after successful liver transplantation. Tumor tissue contained messenger RNA for insulin-like growth factor-II (IGF-II), and circulating high molecular weight components and E-peptide of IGF-II were increased. Glucose use measured by isotope dilution with [3-3H]glucose was 7.94 mg/kg fat-free mass per min, and splanchnic glucose production was 0.93 mg/kg fat-free mass per min. Glucose uptake and glucose model parameters were independently measured in tissues by positron emission tomography with 18F-fluoro-2-deoxy-D-glucose. Glucose uptake by heart muscle, liver, skeletal muscle, and neoplasm accounted for 0.8, 14, 44, and 15% of total glucose use, respectively. Model parameters in liver and neoplasm were not significantly different, and glucose transport and phosphorylation were twofold and fourfold greater than in muscle. This suggests that circulating IGF-II-like proteins are partial insulin agonists, and that hypoglycemia in hepatoma with IGF-II production is predominantly due to glucose uptake by skeletal muscle and suppression of glucose production.

The impact of population education in Baltimore.

PIP: Results of an evaluation of the impact of 1 of 4 population education units offered as part of the 9th grade urban studies curriculum in the Baltimore City school system are reported. The theme of the unit, called B-more or Baltimore, is that Baltimore City has qualities and problems similar to those of other urban areas but is also unique. 908 students exposed to the B-more unit and 205 controls participated in the evaluation in the fall of 1978. Gathering of demographic information on students participating in the evaluation was restricted. The impact of the B-more unit was measured along knowledge, attitude and behavior dimensions through written questionnaires and verbal interview questions. The unit was found to have succeeded in increasing knowledge about Baltimore's resources, increasing ability to utilize these resources, and teaching basic population and urban concepts. Students exposed to the B-more unit were more knowledgeable about their urban environment as illustrated by mapping tasks, and the majority reported that they had learned things that were new and/or important to them from the curriculum. B-more students had more positive attitudes toward the Baltimore suburbs than control students and more negative attitudes toward population growth. Little evidence was noted of changes in behavior resulting from the B-more unit. Recommendations are offered for strengthening the B-more unit and its impact on students.^ieng

Initiating population education in Baltimore.

PIP: At a 3-day workshop in population education for 50 secondary school teachers, 4 members of the Baltimore City Public School system were appointed with 4 members of Planned Parenthood Association of Maryland to deal with the inherent difficulties of bringing population awareness to city children, many of whom in Baltimore are both poor and black. This group believed that it was essential that racial sensitivities, both black and white, be explored in a realistic and humane manner. After considerable soul-searching, it was decided that the approach would be to talk about the city of Baltimore and then demonstrate that Baltimore and its problems represented a microcosm of the world. A pilot institute for 30 selected Baltimore City public school teachers was held in June 1971. The participants of this institute felt that population education should be included in the public school curriculum, and materials to implement this were requested. On the basis of this experiment, the Rockefeller Foundation gave Planned Parenthood Association of Maryland a grant to continue its work with the Baltimore City school system. Nine 3-day Urban Life Population Education Institutes for 30 teachers each were held during school hours in the 1973-1974 school year. All teachers in the system could apply to attend. During the summer of 1973 nine creative and imaginative classroom teachers who had attended an institute were selected to develop curriculum materials. They adopted 6 basic concepts covering the overall view down to the individual level. With the aid of another grant from the Rockefeller Foundation, the materials developed will be piloted in the Baltimore schools during the 1973-1974 session. 10 more institutes for 300 members of the school system will be held during the 1973-1974 school year.^ieng