Validity of a new automated software program for visceral adipose tissue estimation.

INTRODUCTION: Given the considerable time and research cost of analyzing biomedical images to quantify adipose tissue volumes, automated image analysis methods are highly desirable. Hippo Fat is a new software program designed to automatically quantify adipose tissue areas from magnetic resonance images without user inputs. Hippo Fat has yet to be independently validated against commonly used image analysis software programs. OBJECTIVE: Our aim was to compare estimates of VAT (visceral adipose tissue) and SAT (subcutaneous adipose tissue) using the new Hippo Fat software against those from a widely used, validated, computer-assisted manual method (slice-O-matic version 4.2, Tomovision, Montreal, CA, USA) to assess its potential utility for large-scale studies. METHODS: A Siemens Magnetom Vision 1.5-T whole-body scanner and a T1-weighted fast-spin echo pulse sequence were used to collect multiple, contiguous axial images of the abdomen from a sample of 40 healthy adults (20 men) aged 18-77 years of age, with mean body mass index of 29 kg/m(2) (range=19-43 kg/m(2)). RESULTS: Hippo Fat provided estimates of VAT and SAT that were highly correlated with estimates using slice-O-matic (R (2)>0.9). Average VAT was 9.4% lower and average SAT was 3.7% higher using Hippo Fat compared to slice-O-matic; the overestimation of SAT tended to be greater among individuals with greater adiposity. Individual-level differences for VAT were also substantial; Hippo Fattrade mark gave estimates of VAT ranging from 1184 cm(3) less to 566 cm(3) more than estimates for the same person using slice-O-matic. CONCLUSION: Hippo Fat provides a rapid method of quantifying total VAT, although the method does not provide estimates that are interchangeable with slice-O-matic at either the group (mean) or individual level.

Lipids, lipoproteins, lifestyle, adiposity and fat-free mass during middle age: the Fels Longitudinal Study.

INTRODUCTION: Although lipid profiles tend to worsen with age, it is not fully known if such age-related changes are influenced primarily by body composition and lifestyle or by other aspects of aging. OBJECTIVE: We investigated the extent to which the fat and fat-free components of body mass index (BMI) and lifestyle factors influence patterns of change in lipids independent of age. DESIGN: Serial data were analyzed using sex-specific longitudinal models. These models use serial data from individuals to assume a general pattern of change over time, while allowing baseline age and the rate of change to vary among individuals. SUBJECTS: Serial data were obtained from 940 examinations of 269 healthy white participants (126 men, 143 women), aged 40-60 years, in the Fels Longitudinal Study. MEASUREMENTS: Measurements included age, the fat (FMI) and fat-free mass (FFMI) components of BMI, high-density lipoprotein (HDL-C), low-density lipoprotein (LDL-C), triglycerides (TG), total cholesterol (TC), fasting glucose and insulin, physical activity, alcohol use and smoking, and women's menopausal status and estrogen use. RESULTS: In both sexes, increased FMI was significantly associated with increased LDL-C, TG and TC, and decreased HDL-C. Increased FFMI was significantly related to decreased HDL-C and increased TG. Independent age effects remained significant only for LDL-C and TC in men and TC in women. Increased insulin was significantly related to increased TG in women. Moderate alcohol consumption was associated with higher HDL-C in men. Physical activity lowered male LDL-C and TC levels, and increased female HDL-C levels. Menopause was associated with increases in LDL-C. Premenopausal women not using estrogen had significantly lower HDL-C, TG, and TC than postmenopausal women taking estrogen. CONCLUSIONS: (1) Age is an important independent predictor for LDL-C and TC in men, and TC in women, but it is not as influential as body composition and lifestyle on HDL-C and TG in men and women, and LDL-C in women. (2) Increasing FMI is the major contributor to elevated TC, LDL-C and TG levels, and decreased HDL-C levels in men and women. (3) FFMI significantly influences HDL and TG levels in both sexes. (4) Maintaining a lower BMI via a reduced fat component may be more beneficial in lowering CVD risks than other factors.

Evidence for association between polycystic ovary syndrome and premature carotid atherosclerosis in middle-aged women.

Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disorder characterized by obesity, hyperandrogenism, and insulin resistance. An adverse lipid profile has also been observed in PCOS-affected women, suggesting that these individuals may be at increased risk for coronary heart disease at a young age. The objective of the present study was to evaluate subclinical atherosclerosis among women with PCOS and age-matched control subjects. A total of 125 white PCOS cases and 142 controls, aged >/=30 years were recruited. Collection of baseline sociodemographic data, reproductive hormone levels, and cardiovascular risk factors was conducted from 1992 to 1994. During follow-up (1996 to 1999), these women underwent B-mode ultrasonography of the carotid arteries for the evaluation of carotid intima-media wall thickness (IMT) and the prevalence of plaque. A significant difference was observed in the distribution of carotid plaque among PCOS cases compared with controls: 7.2% (9 of 125) of PCOS cases had a plaque index of >/=3 compared with 0.7% (1 of 142) of similarly aged controls (P=0.05). Overall and in the group aged 30 to 44 years, no difference was noted in mean carotid IMT between PCOS cases and controls. Among women aged >/=45 years, PCOS cases had significantly greater mean IMT than did control women (0.78+/-0.03 versus 0.70+/-0.01 mm, P:=0. 005). This difference remained significant after adjustment for age and BMI (P:<0.05). These results suggest that (1) lifelong exposure to an adverse cardiovascular risk profile in women with PCOS may lead to premature atherosclerosis, and (2) the PCOS-IMT association is explained in part by weight and fat distribution and associated risk factors. There may be an independent effect of PCOS unexplained by the above variables that is related to the hormonal dysregulation of this condition.

Diabetes in pregnancy and cesarean delivery.

OBJECTIVE: To evaluate the effect of diabetes during pregnancy on cesarean delivery and to determine whether the association between diabetes during pregnancy and cesarean delivery is mediated by birth weight. RESEARCH DESIGN AND METHODS: South Carolina 1993 birth certificates were matched through a unique identifier with infant and maternal hospital discharge records for the same year, yielding a total study population of 42,071 singleton births. Adjusted odds ratios (ORs) and 95% CIs were determined for the association between diabetes in pregnancy and cesarean delivery through multiple logistic regression, controlling for maternal age, race, education, number of prenatal care visits, length of gestation, birth weight, and a number of medical indications. RESULTS: Of the study population, 0.7% were pregnancies complicated by preexisting diabetes, 2.9% were pregnancies complicated by gestational diabetes, and 23.4% were cesarean deliveries. After controlling for confounders, including birth weight, cesarean delivery was strongly associated with both preexisting diabetes (OR [95% CI] 6.20 [4.47-8.61]) and gestational diabetes (1.71 [1.41-2.07]). The estimates remained essentially unchanged without birth weight in the model, and were substantially higher in analyses restricted to deliveries without common medical indications for cesarean delivery. CONCLUSIONS: Both preexisting and gestational diabetes increase the risk for cesarean delivery, independent of the effect of birth weight. The association is markedly greater among women without other medical indications for cesarean delivery. The increased risk of cesarean delivery for women with diabetes is mediated through other factors, which may include practice patterns and physician referrals to high-risk care.