Metabolomic profiling of glucose homeostasis in African Americans: the Insulin Resistance Atherosclerosis Family Study (IRAS-FS).

INTRODUCTION: African Americans are at increased risk for type 2 diabetes. OBJECTIVES: This work aimed to examine metabolomic signature of glucose homeostasis in African Americans. METHODS: We used an untargeted liquid chromatography-mass spectrometry metabolomic approach to comprehensively profile 727 plasma metabolites among 571 African Americans from the Insulin Resistance Atherosclerosis Family Study (IRAS-FS) and investigate the associations between these metabolites and both the dynamic (SI, insulin sensitivity; AIR, acute insulin response; DI, disposition index; and SG, glucose effectiveness) and basal (HOMA-IR and HOMA-B) measures of glucose homeostasis using univariate and regularized regression models. We also compared the results with our previous findings in the IRAS-FS Mexican Americans. RESULTS: We confirmed increased plasma metabolite levels of branched-chain amino acids and their metabolic derivatives, 2-aminoadipate, 2-hydroxybutyrate, glutamate, arginine and its metabolic derivatives, carbohydrate metabolites, and medium- and long-chain fatty acids were associated with insulin resistance, while increased plasma metabolite levels in the glycine, serine and threonine metabolic pathway were associated with insulin sensitivity. We also observed a differential ancestral effect of glutamate on glucose homeostasis with significantly stronger effects observed in African Americans than those previously observed in Mexican Americans. CONCLUSION: We extended the observations that metabolites are useful biomarkers in the identification of prediabetes in individuals at risk of type 2 diabetes in African Americans. We revealed, for the first time, differential ancestral effect of certain metabolites (i.e., glutamate) on glucose homeostasis traits. Our study highlights the need for additional comprehensive metabolomic studies in well-characterized multiethnic cohorts.

Geometric morphometric analysis of the bony labyrinth of the Sima de los Huesos hominins.

The bony labyrinth contains phylogenetic information that can be used to determine interspecific differences between fossil hominins. The present study conducted a comparative 3D geometric morphometric analysis on the bony labyrinth of the Middle Pleistocene Sima de los Huesos (SH) hominins. The findings of this study corroborate previous multivariate analyses of the SH hominin bony labyrinth. The analysis of the semicircular canals revealed the SH hominin canal morphologies appear closer to those of the Neandertals than to those of Homo sapiens. This is attributable to a Neandertal-like ovoid anterior canal, and mediolaterally expanded, circular posterior canal. However, the SH hominins lack the increased torsion in the anterior canal and the inferior orientation of the lateral canal seen in Neandertals. The results of the cochlear analysis indicated that, although there is some overlap, there are notable differences between the SH hominins and the Neandertals. In particular, the SH hominin cochlea appears more constricted than in Neandertals in the first and second turns. A principal component analysis of the full bony labyrinth separated most SH hominins from the Neandertals, which largely clustered with modern humans. A covariance ratio analysis found a significant degree of modularity within the bony labyrinth of all three groups, with the SH hominins and Neandertals displaying the highest modularity. This modular signal in the bony labyrinth may be attributable to different selective pressures related to locomotion and audition. Overall, the results of this study confirm previous suggestions that the semicircular canals in the SH hominins are somewhat derived toward Neandertals, while their cochlea is largely primitive within the genus Homo.

Mapping environmental crime to characterize human impacts on islands: an applied and methodological research in Canary Islands.

Environmental crimes are a global issue due to the damage they cause to landscapes and ecosystems. This study focused on characterizing environmental crimes in the Canary Islands (Spain). Four categories of environmental crimes related to construction, mining and tilling, solid waste, and liquid waste) were defined and analysed. A total of 28 databases were generated, corresponding to each of the 7 major islands and each environmental crime typology. Each database was linked to information on land use and the socioeconomic and physical characteristics of the territory. For each database, firstly a descriptive statistical analysis was conducted, followed by the generation of a regularized Random Forest model with the aim of identifying characteristics that may be related to the location of environmental crimes. The results showed that, in most cases, proximity to residential accommodations, agricultural areas and industrial zones act as the main explanatory features of the distribution of environmental crimes. Furthermore, a marked pattern of concentration of environmental crimes in the coastal belt of the islands was observed, mainly associated with urban-tourist development since the 1960s and 1970s.

Fatigue characteristics on dialysis and non-dialysis days in patients with chronic kidney failure on maintenance hemodialysis.

BACKGROUND: Fatigue is prevalent in hemodialysis patients who for survival follow a strict dialysis treatment regimen - dialysis and non-dialysis days. As a result, the daily activities, symptom burden, and clinical outcomes of hemodialysis patients vary significantly between dialysis and non-dialysis days. Fatigue is one of the most reported debilitating symptoms by hemodialysis patients with profound negative impact on their quality of life. Prior studies assessed fatigue during the preceding 7 or 30 days and did not discriminate fatigue characteristics between dialysis and non-dialysis days. We aimed to characterize and compare fatigue severity and fatigue interference with daily activities between dialysis and non-dialysis days. METHODS: Hemodialysis patients self-reported fatigue on consecutive dialysis and non-dialysis days using the 9-item Brief Fatigue Inventory. The differences in fatigue characteristics between dialysis and non-dialysis days were analyzed using one-way ANCOVA. RESULTS: Global fatigue burden was worse on a dialysis day compared to a non-dialysis day (P for all < 0.001). Age and education were associated with fatigue, but hemodialysis-related variables were not. A significant inverse association of physical activity with fatigue severity observed on non-dialysis day; there was also a negative association between the normalized protein catabolic rate and fatigue severity on both dialysis and non-dialysis days. The positive association of depression with fatigue severity and fatigue interference were consistent on both dialysis and non-dialysis days. None of these factors, however, explained differences in fatigue characteristics between dialysis and non-dialysis days. CONCLUSIONS: Fatigue, measured in severity and interference, was more pronounced on a dialysis day relative to a non-dialysis day. These differences were not explained by age, sex, education, hemodialysis-related variables, habitual exercise, nutritional status, and or depression. The quantitative measures of fatigue characteristics may facilitate future interventional trials design and better fatigue management for hemodialysis patients.

Pneumatosis intestinalis in anorexia nervosa.

We have read the article by Pérez-Santiago L et al. on the conservative or surgical management of pneumatosis intestinalis (PI). Recently we saw a case of a 18-year-old female diagnosed with anorexia nervosa who presented due to general malaise, asthenia, and inability to walk following an episode of abdominal pain, vomiting and diarrhea (10-15 stools daily, some of them bloody). Physical examination revealed signs of malnutrition and dehydration, and a distended, tender abdomen with no signs of peritoneal irritation. Laboratory chemistry tests revealed macrocytic anemia and metabolic alkalosis. An abdominal CT scan showed pancolonic pneumatosis, with greater involvement of the cecum, ascending and transverse colon, as well as pneumoperitoneum and gas in branches of the superior mesenteric and portal veins.

Branched-Chain Amino Acids Depletion during Hemodialysis Is Associated with Fatigue.

BACKGROUND: Fatigue is one of the most debilitating symptoms reported by maintenance hemodialysis (MHD) patients. Hemodialysis causes marked depletion in plasma essential amino acids. We studied the cross-sectional relationship of pre- and post-hemodialysis branched-chain amino acids (BCAAs) concentrations with fatigue in MHD patients. METHODS: MHD patients self-reported fatigue during a dialysis session using the Brief Fatigue Inventory. Pre- and post-dialysis plasma levels of BCAAs (valine, leucine, and isoleucine) were measured using HPLC-mass spectrometry. RESULTS: The mean age of study participants (n = 114) was 54.8 ± 12.8 years. Plasma levels of BCAAs decreased significantly post-dialysis compared to pre-dialysis (303.8 ± 9.4 vs. 392.1 ± 9.4 µM/L, p < 0.0001). Fatigue score increased as a function of age (p = 0.015). There was no association between pre-dialysis plasma levels of BCAAs and fatigue. A significant negative correlation was found between post-dialysis plasma levels of BCAAs and fatigue (p < 0.05). CONCLUSIONS: These preliminary findings suggest that disruption in BCAAs homeostasis may play a role in precipitating fatigue.

A geometric morphometric approach to the study of sexual dimorphism in the modern human frontal bone.

OBJECTIVES: We analyzed the main anatomical traits found in the human frontal bone by using a geometric morphometric approach. The objectives of this study are to explore how the frontal bone morphology varies between the sexes and to detect which part of the frontal bone are sexually dimorphic. MATERIALS AND METHODS: The sample is composed of 161 skulls of European and North American individuals of known sex. For each cranium, we collected 3D landmarks and semilandmarks on the frontal bone, to examine the entire morphology and separate modules (frontal squama, supraorbital ridges, glabellar region, temporal lines, and mid-sagittal profile). We used Procrustes ANOVAs and LDAs (linear discriminant analyses) to evaluate the relation between frontal bone morphology and sexual dimorphism and to calculate precision and accuracy in the classification of sex. RESULTS: All the frontal bone traits are influenced by sexual dimorphism, though each in a different manner. Variation in shape and size differs between the sexes, and this study confirmed that the supraorbital ridges and glabella are the most important regions for sex determination, although there is no covariation between them. The variable size does not contribute significantly to the discrimination between sexes. Thanks to a geometric morphometric analysis, it was found that the size variable is not an important element for the determination of sex in the frontal bone. CONCLUSION: The usage of geometric morphometrics in analyzing the frontal bone has led to new knowledge on the morphological variations due to sexual dimorphism. The proposed protocol permits to quantify morphological covariation between modules, to calculate the shape variations related to sexual dimorphism including or omitting the variable size.

Insertion sites in manual proximal phalanges of African apes and modern humans.

OBJECTIVES: The primary aim of this study was to describe the insertion sites of the ligaments holding the flexor digitorum profundus and superficialis muscles (flexor ridges) in proximal phalanges 2-5 of African apes and modern humans. To interpret differences in flexor ridge size based on general behavioral differences among taxa. MATERIALS AND METHODS: We analyzed 3D models of manual proximal phalanges 2-5 from 29 gorillas (Gorilla beringei and Gorilla gorilla), 30 chimpanzees (Pan troglodytes) and 36 recent modern humans. Flexor ridges (mm2) were compared within and across genera. RESULTS: Gorillas and chimpanzees had larger flexor ridges for phalanges 2-4 than humans and this difference subsists when controlling for body size. Each genus had a unique insertion size pattern across the digits, with the most heterogeneous pattern found in chimpanzees, followed by humans, and lastly gorillas. These patterns corresponded strongly to the differences in the size of the phalanges within each genus, except for phalanx 5 in humans, which had a larger flexor ridge than expected. DISCUSSION: When comparing these genera, the flexor ridges signal differences between taxa that use their hands for manipulation and locomotion (gorillas and chimpanzees) and taxa that use them exclusively for manipulation (humans). This functional signal was also apparent in the PP5 of humans, whose larger FR may be indicating the high recruitment of this digit during forceful precision grip characteristic of humans.

The cochlea of the Sima de los Huesos hominins (Sierra de Atapuerca, Spain): New insights into cochlear evolution in the genus Homo.

The cochlea contains taxonomic and phylogenetic information and its morphology is related with hearing abilities among fossil hominins. Data for the genus Homo is presently limited to early Homo and the early Neandertals from Krapina. The present study of the middle Pleistocene hominins from the Sima de los Huesos (SH) provides new evidence on cochlear evolution in the genus Homo. We compared the absolute length, proportional lengths of each turn, number of turns, size and shape of the cross-section of the basal turn, volume, curvature gradient, and thickness of the cochlea between extant Pan troglodytes, extant Homo sapiens, Homo neanderthalensis and the SH hominins. The SH hominins resemble P. troglodytes in the proportionally long basal turn, the small size and round shape of the cross-section of the basal turn, the small cochlear volume and the low cochlear thickness. The SH hominins resemble Neandertals and H. sapiens in their long cochlear length and in the proportionally short third turn. Homo neanderthalensis and H. sapiens share several features, not present in the SH hominins, and that likely represent homoplasies: a larger volume, larger size and oval shape of the cross-section of the basal turn and higher cochlear thickness. Later Neandertals show a derived proportionally shorter apical turn. Changes in cochlear volume in Homo cannot be fully explained by variation in body mass or cochlear length but are more directly related to changes in the cross-sectional area of the basal turn. Based on previous studies of the outer and middle ear in SH hominins, changes in the outer and middle ear preceded changes in the inner ear, and the cochlea and semicircular canals seem to have evolved independently in the Neandertal clade. Finally, the small cochlear volume in the SH hominins suggests a slightly higher upper limit of hearing compared with modern humans.

A revision of the conductive hearing loss in Cranium 4 from the Middle Pleistocene site of Sima de los Huesos (Burgos, Spain).

Pathological conditions have been previously documented in the Middle Pleistocene Sima de los Huesos hominins from northern Spain, and several of these have clear behavioral implications. Within this fossil assemblage, Cranium 4 shows bilateral external auditory exostoses which have been preliminarily interpreted as causing a significant hearing loss in this individual. If confirmed, this would be the oldest recorded case of deafness in human history and could have important implications for the antiquity of this condition, as well as social interactions. To further investigate this case, the current study presents 3D reconstructions of the entire outer and middle ear, based on computed tomography scans of both temporal bones in Cranium 4. We established the degree of stenosis in both external auditory canals, showing that in both cases the degree of stenosis is less than 52% of the original cross-sectional area of each canal. Based on clinical studies in living humans, the buildup of wax due to the degree of stenosis in Cranium 4 is unlikely to have caused frequent external ear infections. In addition, we estimated the pattern of sound power transmission up to 5 kHz in both ears relying on a comprehensive model developed in the bioengineering literature and which has been applied previously to the Sima de los Huesos hominins. The model was modified to account for the peculiar shape of the pathological external ear canals in Cranium 4. The results show that this pathology had little to no influence on the sound power transmission in this individual. Thus, we conclude that the exostoses present in both ears of Cranium 4 did not significantly affect their hearing.

Postcranial morphology of the middle Pleistocene humans from Sima de los Huesos, Spain.

Current knowledge of the evolution of the postcranial skeleton in the genus Homo is hampered by a geographically and chronologically scattered fossil record. Here we present a complete characterization of the postcranium of the middle Pleistocene paleodeme from the Sima de los Huesos (SH) and its paleobiological implications. The SH hominins show the following: (i) wide bodies, a plesiomorphic character in the genus Homo inherited from their early hominin ancestors; (ii) statures that can be found in modern human middle-latitude populations that first appeared 1.6-1.5 Mya; and (iii) large femoral heads in some individuals, a trait that first appeared during the middle Pleistocene in Africa and Europe. The intrapopulational size variation in SH shows that the level of dimorphism was similar to modern humans (MH), but the SH hominins were less encephalized than Neandertals. SH shares many postcranial anatomical features with Neandertals. Although most of these features appear to be either plesiomorphic retentions or are of uncertain phylogenetic polarity, a few represent Neandertal apomorphies. Nevertheless, the full suite of Neandertal-derived features is not yet present in the SH population. The postcranial evidence is consistent with the hypothesis based on the cranial morphology that the SH hominins are a sister group to the later Neandertals. Comparison of the SH postcranial skeleton to other hominins suggests that the evolution of the postcranium occurred in a mosaic mode, both at a general and at a detailed level.

Individual serum saturated fatty acids and markers of chronic subclinical inflammation: the Insulin Resistance Atherosclerosis Study.

Recent evidence has documented distinct effects of individual saturated FAs (SFAs) on cardiometabolic outcomes, with potential protective effects from odd- and very long-chain SFAs (VLSFAs). Cross-sectional and prospective associations of individual serum SFAs (12:0, 14:0, 15:0, 16:0, 18:0, 20:0, 22:0, and total SFA) with proinflammatory biomarkers and adiponectin were investigated in 555 adults from the IRAS. Principal component analysis (PCA) of proinflammatory markers yielded three clusters: principal component (PC) 1: fibrinogen, white cell count, C-reactive protein; PC 2: plasminogen activator inhibitor-1 (PAI-1), TNF-α, IL-18; PC 3: IL-6 and IL-8. Cross-sectional analyses on proinflammatory PCs and adiponectin, and prospective analyses on 5 year PAI-1 and fibrinogen concentrations were conducted with multiple regression. Total SFA and 16:0 were positively associated with PC 1 and PC 2, and negatively associated with adiponectin. The 14:0 was positively associated with PC 1 and negatively associated with adiponectin. In contrast, 15:0, 20:0, and 22:0 were negatively associated with PC 2, and 20:0 and 22:0 were positively associated with adiponectin. The 18:0 was negatively associated with PC 3. Prospectively, 15:0, 18:0, 20:0, and 22:0 were negatively associated with 5 year PAI-1 concentrations. The results demonstrate that individual SFAs have distinct roles in subclinical inflammation, highlighting the unique metabolic impacts of individual SFAs.

Analysis of Whole Exome Sequencing with Cardiometabolic Traits Using Family-Based Linkage and Association in the IRAS Family Study.

Family-based methods are a potentially powerful tool to identify trait-defining genetic variants in extended families, particularly when used to complement conventional association analysis. We utilized two-point linkage analysis and single variant association analysis to evaluate whole exome sequencing (WES) data from 1205 Hispanic Americans (78 families) from the Insulin Resistance Atherosclerosis Family Study. WES identified 211,612 variants above the minor allele frequency threshold of ≥0.005. These variants were tested for linkage and/or association with 50 cardiometabolic traits after quality control checks. Two-point linkage analysis yielded 10,580,600 logarithm of the odds (LOD) scores with 1148 LOD scores ≥3, 183 LOD scores ≥4, and 29 LOD scores ≥5. The maximal novel LOD score was 5.50 for rs2289043:T>C, in UNC5C with subcutaneous adipose tissue volume. Association analysis identified 13 variants attaining genome-wide significance (P < 5 × 10-08 ), with the strongest association between rs651821:C>T in APOA5 and triglyceride levels (P = 3.67 × 10-10 ). Overall, there was a 5.2-fold increase in the number of informative variants detected by WES compared to exome chip analysis in this population, nearly 30% of which were novel variants relative to the Database of Single Nucleotide Polymorphisms (dbSNP) build 138. Thus, integration of results from two-point linkage and single-variant association analysis from WES data enabled identification of novel signals potentially contributing to cardiometabolic traits.

Genome-wide linkage and association analysis of cardiometabolic phenotypes in Hispanic Americans.

Linkage studies of complex genetic diseases have been largely replaced by genome-wide association studies, due in part to limited success in complex trait discovery. However, recent interest in rare and low-frequency variants motivates re-examination of family-based methods. In this study, we investigated the performance of two-point linkage analysis for over 1.6 million single-nucleotide polymorphisms (SNPs) combined with single variant association analysis to identify high impact variants, which are both strongly linked and associated with cardiometabolic traits in up to 1414 Hispanics from the Insulin Resistance Atherosclerosis Family Study (IRASFS). Evaluation of all 50 phenotypes yielded 83 557 000 LOD (logarithm of the odds) scores, with 9214 LOD scores ⩾3.0, 845 ⩾4.0 and 89 ⩾5.0, with a maximal LOD score of 6.49 (rs12956744 in the LAMA1 gene for tumor necrosis factor-α (TNFα) receptor 2). Twenty-seven variants were associated with P<0.005 as well as having an LOD score >4, including variants in the NFIB gene under a linkage peak with TNFα receptor 2 levels on chromosome 9. Linkage regions of interest included a broad peak (31 Mb) on chromosome 1q with acute insulin response (max LOD=5.37). This region was previously documented with type 2 diabetes in family-based studies, providing support for the validity of these results. Overall, we have demonstrated the utility of two-point linkage and association in comprehensive genome-wide array-based SNP genotypes.

The bony labyrinth of the middle Pleistocene Sima de los Huesos hominins (Sierra de Atapuerca, Spain).

We performed 3D virtual reconstructions based on CT scans to study the bony labyrinth morphology in 14 individuals from the large middle Pleistocene hominin sample from the site of the Sima de los Huesos (SH) in the Sierra de Atapuerca in northern Spain. The Atapuerca (SH) hominins represent early members of the Neandertal clade and provide an opportunity to compare the data with the later in time Neandertals, as well as Pleistocene and recent humans more broadly. The Atapuerca (SH) hominins do not differ from the Neandertals in any of the variables related to the absolute and relative sizes and shape of the semicircular canals. Indeed, the entire Neandertal clade seems to be characterized by a derived pattern of canal proportions, including a relatively small posterior canal and a relatively large lateral canal. In contrast, one of the most distinctive features observed in Neandertals, the low placement of the posterior canal (i.e., high sagittal labyrinthine index), is generally not present in the Atapuerca (SH) hominins. This low placement is considered a derived feature in Neandertals and is correlated with a more vertical orientation of the ampullar line (LSCm < APA), posterior surface of the petrous pyramid (LSCm > PPp), and third part of the facial canal (LSCm < FC3). Some variation is present within the Atapuerca (SH) sample, however, with a few individuals approaching the Neandertal condition more closely. In addition, the cochlear shape index in the Atapuerca (SH) hominins is low, indicating a reduction in the height of the cochlea. Although the phylogenetic polarity of this feature is less clear, the low shape index in the Atapuerca (SH) hominins may be a derived feature. Regardless, cochlear height subsequently increased in Neandertals. In contrast to previous suggestions, the expanded data in the present study indicate no difference across the genus Homo in the angle of inclination of the cochlear basal turn (COs < LSCm). Principal components analysis largely confirms these observations. While not fully resolved, the low placement of the posterior canal in Neandertals may be related to some combination of absolutely large brain size, a wide cranial base, and an archaic pattern of brain allometry. This more general explanation would not necessarily follow taxonomic lines, even though this morphology of the bony labyrinth occurs at high frequencies among Neandertals. While a functional interpretation of the relatively small vertical canals in the Neandertal clade remains elusive, the relative proportions of the semicircular canals is one of several derived Neandertal features in the Atapuerca (SH) crania. Examination of additional European middle Pleistocene specimens suggests that the full suite of Neandertal features in the bony labyrinth did not emerge in Europe until perhaps <200 kya.

Fossil hominin radii from the Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain).

Complete radii in the fossil record preceding recent humans and Neandertals are very scarce. Here we introduce the radial remains recovered from the Sima de los Huesos (SH) site in the Sierra de Atapuerca between 1976 and 2011 and which have been dated in excess of 430 ky (thousands of years) ago. The sample comprises 89 specimens, 49 of which are attributed to adults representing a minimum of seven individuals. All elements are described anatomically and metrically, and compared with other fossil hominins and recent humans in order to examine the phylogenetic polarity of certain radial features. Radial remains from SH have some traits that differentiate them from those of recent humans and make them more similar to Neandertals, including strongly curved shafts, anteroposterior expanded radial heads and both absolutely and relatively long necks. In contrast, the SH sample differs from Neandertals in showing a high overall gracility as well as a high frequency (80%) of an anteriorly oriented radial tuberosity. Thus, like the cranial and dental remains from the SH site, characteristic Neandertal radial morphology is not present fully in the SH radii. We also analyzed the cross-sectional properties of the SH radial sample at two different levels: mid-shaft and at the midpoint of the neck length. When standardized by shaft length, no difference in the mid-shaft cross-sectional properties were found between the SH hominins, Neandertals and recent humans. Nevertheless, due to their long neck length, the SH hominins show a higher lever efficiency than either Neandertals or recent humans. Functionally, the SH radial morphology is consistent with more efficient pronation-supination and flexion-extension movements. The particular trait composition in the SH sample and Neandertals resembles more closely morphology evident in recent human males.

Morphometric patterns among the 3D surface areas of human hand entheses.

OBJECTIVES: This study aimed to put forth a new and precise methodology for calculating the 3D areas of hand entheses. Furthermore, it investigated some of the factors affecting hand entheses development through an assessment of their correlations and morphometric patterns. MATERIALS AND METHODS: Fifty individuals from late-medieval San Pablo were studied. The sample consisted of high-definition 3D models of 17 entheses from the first, second, and fifth hand rays. A new methodology was introduced for quantifying their areas. Precision was verified using intraobserved and interobserver tests. Both raw and relative entheseal size (ratio of entheseal size to total bone surface size) were calculated. Bivariate analyses assessed the effect of age-group on entheses as well as the correlations across entheses of muscles that act synergistically, bone length, and articular surface size. The morphometric patterns among hand entheses were explored using a multivariate analysis. RESULTS: The methodology presented no significant error. Age-group variation does not seem to affect hand entheses. In relative size, only particular pairs presented significant association and the entheses involved were not correlated with bone length or articular surface size. The multivariate analysis demonstrated high sexual dimorphism in overall entheseal size as well as two morphometric trends among hand entheses. DISCUSSION: The proposed methodology can set the basis for further morphological 3D analysis of entheses. If biomechanical stress affects hand entheses, its impact would possibly be greater on their relative size. The morphometric patterns among entheses seem to reflect the performance of prehensile grips. Am J Phys Anthropol 160:694-707, 2016. © 2016 Wiley Periodicals, Inc.

Diploic vessels and computed tomography: Segmentation and comparison in modern humans and fossil hominids.

OBJECTIVES: The diploic channels appear to be more developed in humans than in nonhuman primates, suggesting they may be relevant in evolutionary biology. This study is aimed at providing a segmentation procedure for diploic channels and CT analysis, a quantitative description of their variation in modern humans, and paleoanthropological case-studies. MATERIALS AND METHODS: CT data were used for the 2D and 3D visualization, rendering, and measure, of diploic channels in modern and fossil hominids. We analyzed 20 modern human skulls and three Neanderthals. The effect of different resolution factors was evaluated. A specific protocol was designed to segment the vascular network and localize the main branches, reducing the noise of the cancellous bone. RESULTS: We provide a quantitative description of the frontal, parietal, and occipital diploic networks in modern humans and in three Neanderthals. There is a correlation in the degree of vascularization among the different vault areas. No side differences can be detected. The diploic network is commonly connected with the meningeal artery at the temporal fossa, with the emissary veins at the occipital bone, and with the venous sinuses at the parieto-occipital areas. The channels are more developed in the parietal areas. The three Neanderthals show a vascular development, which is in the lower range of the modern human variation. CONCLUSIONS: Modern humans display a large variation in their morphological patterns, being the parietal area the most vascularized. The pattern of the diploic channels may be relevant in anthropology, medicine, and paleontology, taking into account their possible involvement in thermoregulation.

Lipoprotein heterogeneity may help to detect individuals with insulin resistance.

AIMS/HYPOTHESIS: The triacylglycerol (TG)-to-HDL-cholesterol ratio has been shown to detect insulin resistance. However, the added predictive value of a more comprehensive assessment of lipoprotein composition is unknown. METHODS: We analysed cross-sectional data from 882 non-diabetic participants in the Insulin Resistance Atherosclerosis Study (IRAS). Lipoproteins were measured by nuclear magnetic resonance (NMR) spectroscopy. Determined by the frequently sampled intravenous glucose tolerance test, insulin resistance was defined as the lowest sex-specific quartile of insulin sensitivity. RESULTS: The AUC of the receiver operating characteristic curve of HDL-cholesterol and TG levels for detecting insulin resistance was similar to that of the TG-to-HDL-cholesterol ratio (0.676 vs 0.673; p = 0.685), but smaller than the AUC of NMR-detected lipoproteins (0.676 vs 0.745; p < 0.001). NMR lipoproteins added discriminative value to HDL-cholesterol and TG levels (net reclassification improvement of 40.0%; p < 0.001; and integrated discrimination improvement of 9.5%; p < 0.001), with net benefit within predicted probabilities of between 10% and 50% by Vickers' decision-curve analysis. We also demonstrated additive value to demographic variables, BMI and levels of fasting glucose, TG, and HDL-cholesterol (net reclassification improvement of 14.0%; p < 0.001; and integrated discrimination improvement of 4.5%; p < 0.001). CONCLUSIONS/INTERPRETATION: NMR lipoproteins, which can be measured in the fasting state, add information to the TG and HDL-cholesterol ratio across a broad range on insulin resistance. Depending on the other risk factors of insulin resistance that are incorporated, NMR lipoproteins permit the correct reclassification of an additional 14-40% of individuals.