Effect of gender on intra-abdominal fat in teenagers and young adults

Correlating Abdominal Wall Thickness and Body Mass Index to Predict Usefulness of Right Lower Quadrant Ultrasound for Evaluation of Pediatric Appendicitis

OBJECTIVES

To inform selective and efficient use of appendix ultrasound (US) beyond adult parameters of body mass index (BMI) of less than 25 kg/m, we correlate abdominal wall thickness (AWT) with age and BMI to generate parameters for male and female children. Information presented in chart format can aid in the decision to utilize US for the evaluation of appendicitis.

METHODS

In this observational study, 1600 pediatric computed tomography scans of the abdomen and pelvis were analyzed to obtain measurements of AWT in the right lower quadrant. Measurements were correlated by patient age, BMI, and sex. Results and consensus-based recommendations were presented in chart format with color-coded groupings to allow for convenient referencing in the clinical setting.

RESULTS

One thousand four hundred eighty-eight computed tomography scans and AWT measurements were included. All age groups with BMI of less than 25 kg/m and all male and female groups younger than 6 years regardless of BMI had median AWT of less than 4 cm resulting in strong recommendation for US. Males older than 6 years and all female age groups with BMI of greater than 30 kg/m and female older than 15 years and BMI of greater than 25 kg/m had AWT of more than 5 cm resulting in low recommendation for US.

CONCLUSIONS

While the BMI cutoff standard of less than 25 kg/m for usefulness of appendix US holds in the adult population, our data expand the acceptable range in children younger than 9 years regardless of BMI and male children with BMI up to 30 kg/m. Female children younger than 15 years with a BMI up to 30 kg/m may also be amenable to right lower quadrant US based on AWT. These parameters inform selective and efficient use of US for appendix evaluation.

Increased Abdominal Adiposity in Adolescents and Young Adults With Classical Congenital Adrenal Hyperplasia due to 21-Hydroxylase Deficiency

CONTEXT

Childhood obesity rates in congenital adrenal hyperplasia (CAH) exceed the high rates seen in normal children, potentially increasing their risk of cardiovascular disease (CVD). Abdominal adiposity, in particular visceral adipose tissue (VAT), is strongly associated with metabolic syndrome and CVD. However, it remains unknown whether VAT is increased in CAH.

OBJECTIVE

The objective of the study was to determine whether adolescents and young adults with classical CAH have more VAT and sc adipose tissue (SAT) than matched controls and whether VAT and SAT are associated with biomarkers of metabolic syndrome, inflammation, and hyperandrogenism in CAH.

DESIGN/SETTING

This was a cross-sectional study at a tertiary center.

PARTICIPANTS

CAH subjects (n = 28; 15.6 ± 3.2 y; 15 females) were matched for age, sex, ethnicity, and body mass index to healthy controls (n = 28; 16.7 ± 2.3 y; 15 females).

MAIN OUTCOME MEASURES

VAT and SAT, using computed tomography imaging and serum biomarkers associated with CVD risk, were measured. Data are reported as mean ± SD.

RESULTS

Both VAT (43.8 ± 45.5 cm(2)) and SAT (288.1 ± 206.5 cm(2)) were higher in CAH subjects than controls (VAT 26.4 ± 29.6 cm(2) and SAT 226.3 ± 157.5 cm(2); both P < .001). The VAT to SAT ratio was also higher in CAH subjects (0.15 ± 0.07) than controls (0.12 ± 0.06; P < .05). Within CAH, measures of obesity (waist to height ratio, fat mass) and inflammation (plasminogen activator inhibitor-1, high-sensitivity C-reactive protein, leptin) correlated strongly with VAT and SAT. In addition, homeostasis model assessment of insulin resistance, and low-density lipoprotein correlated with abdominal adiposity. There were no sex differences for VAT or SAT in CAH subjects.

CONCLUSIONS

CAH adolescents and young adults have increased abdominal adiposity, with a higher proportion of proinflammatory VAT than SAT. An improved understanding of the mechanism of obesity in CAH may lead to targeted prevention and therapeutics in this high-risk population.

Female mice are more susceptible to nonalcoholic fatty liver disease: sex-specific regulation of the hepatic AMP-activated protein kinase-plasminogen activator inhibitor 1 cascade, but not the hepatic endotoxin response

As significant differences between sexes were found in the susceptibility to alcoholic liver disease in human and animal models, it was the aim of the present study to investigate whether female mice also are more susceptible to the development of non-alcoholic fatty liver disease (NAFLD). Male and female C57BL/6J mice were fed either water or 30% fructose solution ad libitum for 16 wks. Liver damage was evaluated by histological scoring. Portal endotoxin levels and markers of Kupffer cell activation and insulin resistance, plasminogen activator inhibitor 1 (PAI-1) and phosphorylated adenosine monophosphate-activated protein kinase (pAMPK ) were measured in the liver. Adiponectin mRNA expression was determined in adipose tissue. Hepatic steatosis was almost similar between male and female mice; however, inflammation was markedly more pronounced in livers of female mice. Portal endotoxin levels, hepatic levels of myeloid differentiation primary response gene (88) (MyD88) protein and of 4-hydroxynonenal protein adducts were elevated in animals with NAFLD regardless of sex. Expression of insulin receptor substrate 1 and 2 was decreased to a similar extent in livers of male and female mice with NAFLD. The less pronounced susceptibility to liver damage in male mice was associated with a superinduction of hepatic pAMPK in these mice whereas, in livers of female mice with NAFLD, PAI-1 was markedly induced. Expression of adiponectin in visceral fat was significantly lower in female mice with NAFLD but unchanged in male mice compared with respective controls. In conclusion, our data suggest that the sex-specific differences in the susceptibility to NAFLD are associated with differences in the regulation of the adiponectin-AMPK-PAI-1 signaling cascade.

Differential effect of gender on hepatic fat

BACKGROUND

There are discrepant data on whether men or women have a higher risk for hepatic steatosis.

OBJECTIVE

To examine the influence of gender on hepatic adiposity in teenagers and young adults.

MATERIALS AND METHODS

We measured subcutaneous abdominal fat (SAF), intra-abdominal fat (IAF) and hepatic tissue density (a surrogate measure of hepatic fat) using CT in 505 healthy teenagers and young adults (254 males, 251 females; ages 15-22.9 years).

RESULTS

Overall, compared to men, women had higher values of SAF (P < 0.0001) but similar measures of IAF and liver tissue density (P = 0.09 and 0.92, respectively). However, when compared to overweight/obese men, overweight/obese women had strikingly similar IAF values (P = 0.85) but lower hepatic fat (P = 0.009). Multiple regression analyses indicated that, after adjusting for age and SAF, IAF independently predicted hepatic density in males (P < 0.0001) but not in females (P = 0.36). Hepatic fat increased with body mass in males from lean to overweight and obese (P < 0.0001) but not in females (P > 0.05).

CONCLUSION

When compared to overweight and obese young women, overweight and obese young men are at greater risk for hepatic steatosis, independent of IAF.