Jennifer L. Rehm

Adipose Tissue MRI for Quantitative Measurement of Central Obesity

To validate adipose tissue magnetic resonance imaging (atMRI) for rapid, quantitative volumetry of visceral adipose tissue (VAT) and total adipose tissue (TAT).

Quantification of liver fat with respiratory-gated quantitative chemical shift encoded MRI

To evaluate free‐breathing chemical shift‐encoded (CSE) magnetic resonance imaging (MRI) for quantification of hepatic proton density fat‐fraction (PDFF). A secondary purpose was to evaluate hepatic R2* values measured using free‐breathing quantitative CSE‐MRI.

Predicting Hepatic Steatosis in a Racially and Ethnically Diverse Cohort of Adolescent Girls

OBJECTIVE To develop a risk assessment model for early detection of hepatic steatosis using common anthropometric and metabolic markers. STUDY DESIGN This was a cross-sectional study of 134 adolescent and young adult females, age 11-22 years (mean 13.3±2 years) from a middle school and clinics in Madison, Wisconsin. The ethnic distribution was 27% Hispanic and 73% non-Hispanic; the racial distribution was 64% Caucasian, 31% African-American, and 5% Asian, Fasting glucose, fasting insulin, alanine aminotransferase (ALT), body mass index (BMI), waist circumference (WC), and other metabolic markers were assessed. Hepatic fat was quantified using magnetic resonance imaging proton density fat fraction (MR-PDFF). Hepatic steatosis was defined as MR-PDFF>5.5%. Outcome measures were sensitivity, specificity, and positive predictive value (PPV) of BMI, WC, ALT, fasting insulin, and ethnicity as predictors of hepatic steatosis, individually and combined, in a risk assessment model. Classification and regression tree methodology was used to construct a decision tree for predicting hepatic steatosis. RESULTS MR-PDFF revealed hepatic steatosis in 16% of subjects (27% overweight, 3% nonoverweight). Hispanic ethnicity conferred an OR of 4.26 (95% CI, 1.65-11.04; P=.003) for hepatic steatosis. BMI and ALT did not independently predict hepatic steatosis. A BMI>85% combined with ALT>65 U/L had 9% sensitivity, 100% specificity, and 100% PPV. Lowering the ALT value to 24 U/L increased the sensitivity to 68%, but reduced the PPV to 47%. A risk assessment model incorporating fasting insulin, total cholesterol, WC, and ethnicity increased sensitivity to 64%, specificity to 99% and PPV to 93%. CONCLUSION A risk assessment model can increase specificity, sensitivity, and PPV for identifying the risk of hepatic steatosis and guide the efficient use of biopsy or imaging for early detection and intervention.

Ethnic differences in the effects of hepatic fat deposition on insulin resistance in nonobese middle school girls

In nonobese youth, to investigate whether hepatic fat deposition and its metabolic consequences vary between ethnic groups.

In Nonobese Girls, Waist Circumference as a Predictor of Insulin Resistance Is Comparable to MRI Fat Measures and Superior to BMI

Objective: The aim of this study was to investigate the degree to which waist circumference (WC), body mass index (BMI), and magnetic resonance imaging (MRI)-measured abdominal fat deposition predict insulin resistance (IR) in nonobese girls of diverse racial and ethnic backgrounds. Methods: Fifty-seven nonobese girls (12 African-American, 16 Hispanic White, and 29 non-Hispanic White girls) aged 11-14 years were assessed for WC, MRI hepatic proton density fat fraction, visceral and subcutaneous adipose tissue volume, BMI Z-score, fasting insulin, homeostasis model of assessment (HOMA)-IR, adiponectin, leptin, sex hormone-binding globulin, high-density lipoprotein cholesterol, and triglycerides. Results: Univariate and multivariate analyses adjusted for race and ethnicity indicated that only WC and visceral adipose tissue volume were independent predictors of fasting insulin and HOMA-IR, while hepatic proton density fat fraction, BMI Z-score, and subcutaneous adipose tissue volume were dependent predictors. Hispanic White girls showed significantly higher mean fasting insulin and HOMA-IR and lower sex hormone-binding globulin than non-Hispanic White girls (p < 0.01). Conclusions: In nonobese girls of diverse racial and ethnic backgrounds, WC, particularly when adjusted for race or ethnicity, is an independent predictor of IR comparable to MRI-derived measurements of fat and superior to the BMI Z-score.

Complexity in the Diagnosis and Management of 45,X Turner Syndrome Mosaicism

Diagnosis, decision making, and counseling for patients with disorders of sexual development pose challenges for physicians and families. Accurate antenatal evaluation combined with effective communication between the family and multidisciplinary team is important to provide the best patient outcome. We reviewed 2 cases from our institution that illustrate the complexity of antenatal and postnatal management in Turner Syndrome patients who have 45,X mosaicism. We concluded that because of the complexity involved in providing appropriate care to these individuals, it is critical that accurate and universally accessible counseling materials are available to providers and families at the time of diagnosis and management decision making.

Curative potential of allogeneic hematopoietic stem cell transplant in type 1 diabetes.

The mainstay of treatment for type 1 diabetes (T1D) is exogenous insulin. Here, we report a case in which exogenous insulin requirements were eliminated after an allogeneic hematopoietic stem cell transplant for aplastic anemia in a pediatric patient recently diagnosed with T1D, and explore the validity of this approach compared with current treatments.