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PubMed1997

Predictors of Success on the NATABOC Certification Examination.

OBJECTIVE: To determine the degree to which a selected number of variables could predict success on the first attempt at the National Athletic Trainers' Association Board of Certification Examination. DESIGN AND SETTING: Data were obtained from the student records of subjects who were enrolled in the same undergraduate athletic training education program for a minimum of two years, maintained a minimum GPA of 2.5 on a 4.0 scale, and had taken the National Athletic Trainers' Association Board of Certification Examination. A telephone survey of the subjects was used to supplement these records. SUBJECTS: Fifty-two subjects (38 male, 14 female) who had been enrolled for a mean of seven semesters (+/-2.57) participated in this study. Subjects maintained a mean overall GPA of 3.27 (+/- 0.39), with an athletic training mean GPA of 3.34 (+/-0.43) and an academic minor mean GPA of 2.91 (+/-0.46). The mean ACT composite score was 18 (+/-4.02). MEASUREMENTS: Subjects sat for the National Athletic Trainers' Association Board of Certification Examination. Examination passing status, rather than subjects' scores on individual sections, was used in the analysis. RESULTS: Analysis using forward multiple linear regression indicated that no single independent variable predicted examination success. However, a strong interrelationship was present between several of the independent variables. Multiple discriminant analysis was used to determine the nature and strength of these interrelationships. A composite set of variables was formed to include overall academic GPA, athletic training GPA, academic minor GPA, ACT composite score, and number of semesters of university enrollment. This composite set explained 42% of the variance in predicting successful completion of the entire examination on the first attempt. The predictive power of the composite set greatly decreased after the first examination attempt. CONCLUSIONS: Academic variables are the strongest predictors of first-time success on the overall National Athletic Trainers' Association Board of Certification Examination and its component sections.

Journal Article↗

PubMed1977

Correlates of maximal oxygen consumption during treadmill exercise.

According to the Balke treadmill protocol, 39 healthy male USAF volunteers were subjected to maximal exercise. The subjects as a group passed the anaerobic threshold by the end of exercise since average venous lactate concentrations increased from 11.2 +/- 1.6 mg% (95% confidence limits) to 93.0 +/- 8.5 mg% (95% confidence limits), and the average gas exchange ratio (R) at the end of the exercise was greater than unity (p less than 0.0005). Tests for correlations showed weak but statistically significant (p less than 0.05) relationships between change in venous lactic acid concentrations and R (r = 0.44) and maximal heart rate (r = 0.34). Maximal oxygen consumption was correlated with time of exercise (r = 0.70) and subject weight (r = 0.33). Subject age and initial plasma lactate concentrations were not significantly correlated with any other variables. Multiple linear regression yielded an equation for prediction of maximal oxygen consumption which included terms for time of exercise and subject weight. Although the multiple correlation coefficent (r = 0.75) was statistically significant (p less than 0.05), it was considered insufficient for accurate prediction of maximal oxygen consumption.

Adult↗

PubMed2002

Prediction of unbound propofol concentrations in a diabetic population.

Propofol is a short-acting general intravenous anesthetic characterized by a wide interindividual variability in the response after the same dose. Its binding to serum proteins exceeds 98%, so small changes in protein concentrations can be amplified in the unbound fraction of the drug and hence possibly in the effect. It is then likely that part of the variability in the response could be attributed to differences in protein levels among individuals and particularly among those with pathologies such as diabetes. The aim of this study was to establish predictive regression models in a diabetes mellitus (DM) population between unbound:bound propofol ratios and demographic and biochemical indices. Unbound:bound propofol ratios can be routinely obtained in the clinic as opposed to the free fraction of the drug. In DM patients (30 women and 37 men aged between 17 and 78 y) with mellitus type 1 (n = 37) and type 2 (n = 30) diabetes, the authors measured the lipoproteins (HDL, LDL, and VLDL), cholesterol, triglycerides, albumin, alpha1-acid glycoprotein (AAG), free fatty acids (FFA), glycosylated hemoglobin, and the unbound fraction (Fu) and the bound/free ratio (B/F) of propofol. A linearized regression model between the above variables--as well as age, sex, and type of diabetes--and Fu was then developed. Patients had blood drawn and sera separated by centrifugation and spiked with propofol to a concentration of 10 microg/mL. The Fu was determined via ultrafiltration. Multiple linear regression analysis was used to identify significant predictor variables of Fu in this population and two models were originated: one with lipoprotein serum concentrations as explanatory variables (Model A) and another that depended on cholesterol and triglycerides (Model B). Both models presented high correlation coefficients (r2 = 0.71 and 0.68, respectively; P < 0.0001), and each was used to predict Fu in an independent group of 15 DM patients of similar characteristics and biochemical indices as the model development group. Bias and precision were for Model A, 0.9% and 7.8%, and for Model B, 3.0% and 8.7%, respectively. Both models were compared with each other and to a naive predictor (the mean) and each was better than the naive model in predicting the unbound fraction of propofol. Model A and model B could be used in estimating Fu of propofol in DM patients based on the more routine clinical measures of lipoprotein serum concentrations or cholesterol and triglyceride levels.

Adolescent↗

PubMed1998

Urinary excretion of the pyridinium cross-links of collagen in systemic lupus erythematosus.

The aim of this study was to measure the urinary excretion of the pyridinium cross-links of collagen and to determine their usefulness as markers of reduced bone mineral density in systemic lupus erythematosus (SLE). All female SLE patients managed at a single centre were invited to participate in a cross-sectional study of urinary pyridinium cross-links excretion (HPLC), bone mineral density (DXA), and SLE-related variables. Ninety-one women with SLE were studied, 35 of whom were postmenopausal. Pyridinoline/Creatinine (Pyd/Cr) and deoxypyridinoline/Cr (Dpd/Cr) levels in postmenopausal women were significantly increased compared with premenopausal values (p = 0.010 and p = 0.004, respectively). Univariate linear regression analysis revealed a significant association of Dpd/Cr with reduced femoral neck and lumbar spine BMD (p = 0.001, p<0.001), and of Pyd/Cr with reduced femoral neck BMD (p = 0.020). In addition, the association of Pyd/Cr with reduced lumbar spine BMD approached significance (p = 0.055). Stepwise multiple linear regression analysis adjusting for other variables confirmed a significant association of Dpd/Cr with reduced lumbar spine BMD (p = 0.006), and a significant association of both Pyd/Cr and Dpd/Cr with postmenopausal status (p = 0.003, p<0.001). It was concluded that in this SLE population, the urinary excretion of Dpd/Cr was a useful marker of reduced BMD at the lumbar spine. Menopausal status was a major predictor of cross-links excretion in SLE.

Absorptiometry, Photon↗

PubMed1995

The relationship between osteoarthritis of the hands, bone mineral density, and osteoporotic fractures in elderly women.

To study the relationship between osteoarthritis (OA) and osteoporosis (OP), radiographic osteoarthritis lesions of the hands (HOA) were quantified in 300 healthy women, aged 75 years or more, as a subgroup of a cohort originally recruited for a multi-centre study of risk factors for femoral neck fracture. The HOA combined score (i.e. the sum of the grades of joint-space narrowing, osteophytes, erosions and joint misalignment), the osteophytosis score and the joint-space narrowing score were calculated on a radiograph of both hands. Bone mineral density (BMD) was measured using dual-energy X-ray absortiometry (Lunar DPX) at the femoral neck, Ward's triangle and the total body. BMDs of the total spine, lumbar spine, and the upper and lower limbs were derived from the regional analyses of the total body measurement. Correlations between bone mass, HOA scores and other variables were explored by multiple linear regression and stepwise logistic regression analysis. The HOA combined score was positively correlated with increasing age but not with body mass index. In the multiple regression analyses the HOA combined score positively correlated with BMD and the joint-space narrowing score. According to stepwise logistic regression and after off adjustment of BMD for age, women with an HOA combined score higher than 20 had significantly higher BMD values at all skeletal sites. Sixty-nine women (23%) reported a history of osteoporotic fracture; among them, 20 (6.6%) reported a history of vertebral fracture. The OA score of both subgroups was significantly lower than that of women with no history of fracture. These data suggest that in elderly women the severity of HOA is positively correlated with bone mass and that women with a higher score of HOA more rarely report a history of osteoporotic fracture.

Aged↗

PubMed2003

Ethnic differences in birth weight by gestational age: at least a partial explanation for the Hispanic epidemiologic paradox?

OBJECTIVE: The purpose of this study was to evaluate ethnic differences in low birth weight and gestational age-dependent birth weight. STUDY DESIGN: A retrospective cohort study of 47,669 newborn infants was conducted with the use of the perinatal database of the Memorial Health Care System. Logistic regression was used to estimate the odds ratio for low birth weight by ethnic group, which took into account gestational age at delivery. Multiple linear regression models were then developed to predict ethnic differences in birth weight by gestational age. RESULTS: When compared with white women, the adjusted odds ratio for low birth weight in of Mexican origin women (1.16; 95% CI, 1.02-1.32) was substantially lower than that of African American women (2.21; 95% CI, 1.87-2.60). An analysis of birth weight by gestational age suggested that African American neonates were intrinsically smaller than Hispanic neonates (difference, 4.22%). CONCLUSION: At least some of the differences in low birth weight that are noted among ethnic minorities may be attributable to ethnic differences in birth weight by gestational age.

Black or African American↗

PubMed1999

Factors contributing to a prolonged stay after ambulatory surgery.

UNLABELLED: We identified predictors for prolonged postoperative stay after ambulatory surgery using multiple logistic regression models. We collected perioperative data for 16,411 ambulatory surgical patients. A log-transformed time to discharge variable was modeled by multiple linear regression, including patient-, anesthesia-, and surgery-specific variables. The impact of hypothetical elimination of perioperative adverse events on mean length of stay was also estimated. Separate analyses were performed among patients who received general anesthesia (GA) and monitored anesthesia care (MAC). Patients receiving GA stayed 50 min longer than patients receiving MAC. Patients receiving GA and undergoing strabismus, transurethral, or otorhinolaryngological/dental procedures had the longest postoperative stay. Among patients receiving GA, smokers had a 4% shorter stay compared with nonsmokers; among patients receiving MAC, those with congestive heart failure (CHF) had a 11% longer stay compared with patients without CHF. Postoperative nausea and vomiting, dizziness, excessive pain, and cardiovascular events predicted 22%-79% increases in postoperative stay. The hypothetical elimination of all adverse events resulted in a 9.6% decrease in mean length of stay among patients receiving GA, but in only a 3.8% decrease among patients receiving MAC. The length of postoperative stay among ambulatory surgical patients is mainly determined by the type of surgery and by adverse events, such as excessive pain, postoperative nausea and vomiting, dizziness, drowsiness, and cardiovascular events. Patients with CHF and those who underwent long procedures had a higher risk of a prolonged stay. Appropriate prevention and management of postoperative symptoms could significantly decrease the length of stay among patients receiving GA. IMPLICATIONS: The length of postoperative stay among ambulatory surgical patients is mainly determined by the type of surgery and by adverse events, such as excessive pain, postoperative nausea and vomiting, dizziness, drowsiness, and untoward cardiovascular events. Patients with congestive heart failure and those who underwent long procedures had a higher risk of a prolonged stay. Appropriate prevention and management of postoperative symptoms could significantly decrease the length of stay among patients receiving general anesthesia.

Adult↗

PubMed1996

The influence of age and cardiorespiratory fitness on kinetics of oxygen uptake.

The purpose of this study was to determine the influences of ageing and cardiorespiratory fitness on kinetics of VO2 during the transition to exercise of moderate intensity. Subjects performed three transitions to and from a 6-minute square wave constant load, at an intensity corresponding to 90% of ventilatory threshold (VET), to determine VO2 kinetics. The young group had a significantly faster time constant of VO2 (tau VO2). Tau VO2 was significantly correlated with VO2max for both young and old groups; however, the slope of the tau VO2--VO2max regression equation was steeper for the old group, indicating that fit older subjects had VO2 kinetics that approached those of fit young. A multiple linear regression indicated that relative fitness was the strongest significant predictor of tau VO2, followed by sex and age. Although VO2 kinetics are definitely slowed with age, relative levels of cardiorespiratory fitness also have a great influence on the dynamic response of VO2.

Adult↗

PubMed1992

[Value of combined electro- and vectorcardiography in the estimation of left ventricular mass in the elderly].

Electro- and vectorcardiographic methods describe left ventricle increases only when it has attained a significantly high magnitude, but even in such circumstances the exactitude of such methods is substantially lower than that of echocardiogram (ECHO). On the other hand, in comparison to other age groups, there have been relatively few reports relating electrocardiogram (ECG), vectorcardiogram (VCG) and ECHO with left ventricular mass (LVM) in healthy elderly subjects where increases of the left ventricle mass, if present, would be small or moderate. In this paper LVM as well as LVM index (iLVM) from a group of healthy subjects belonging to a physical training program for elderly, was studied by means of ECHO and computerized ECG and VCG. From ECG, voltage indexes and other LVM associated parameters were extracted; from VCG, planar maximum vectors, areas within VCG loops and maximal spatial magnitude of QRS (SM), were measured. Results of LVM (221 +/- 37.9, g) were higher than figures reported for others groups. Voltage indexes showed normal values, but QRS duration was somewhat prolonged. The best simple linear regression, combining variables from VCG and ECG was maximum horizontal vector (Vmax-Hor) vs Sokolow-Lyon index (SOK) and combining ECHO with ECG or VCG, LVM vs Area inside horizontal loop (AreaHor). A model for estimation of LVM from electrical variables was obtained by multiple linear regression; combining five variables from ECG and VCG. The best model included Sokolow-Lyon index and variables from horizontal and sagittal planes of VCG and spatial magnitude of QRS: LVM = 4.8 SOK-186 VmaxHOR-80 VmaxSAG + 126SM + 340 AreaH + 175.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1990

Alcohol consumption as a risk factor for high blood pressure from the Cardiovascular Diseases and Alimentary Comparison Study. CARDIAC Cooperative Research Group).

The relationship between alcohol consumption and blood pressure (BP) was studied in 29 centers in 12 countries as part of the International Cooperative Cardiovascular Diseases and Alimentary Comparison (CARDIAC) Study. From each population, 100 men and 100 women aged 50-54 were randomly selected for BP measurement by automated system and for a standardized interview to complete the questionnaire relating to alcohol consumption. In cross-center simple linear regression analysis, mean alcohol consumption calculated from a previous week's drinking did not show a linear association to BP. In within-center multiple linear regression analysis, relationships between high alcohol intake (much greater than 300 g/week) and BP were assessed among 26 centers with high alcohol drinkers after being adjusted for other confounding variables. Positive associations of high alcohol intake with systolic BP (SBP) and diastolic BP (DBP) were noted in 17 and 16 centers, respectively. Thus, high alcohol intake was positively and independently associated with BP in individual subjects.

Alcohol Drinking↗

PubMed1989

Productivity of the clinical dietitian: measurement by a regression model.

Productivity of 283 clinical dietitians employed in 40-bed to 1,200-bed medical centers and community and general hospitals nationwide was measured from a survey. Stepwise multiple linear regression statistical analyses were used to analyze data. Five measures of productivity were developed; hours in non-patient care divided by total hours worked and the activity level in activities nonproductive in relation to the job description activities produced the better models for measuring productivity of the clinical dietitian. Activity levels measured in the study showed high-level task activities (consuming a large amount of work time) were conducting individual diet instructions, conducting nutrition assessments, reviewing and recording in medical records, and supervising support personnel. Taking anthropometric measurements, participating in medical rounds, attending professional conferences, and purchasing and dispensing specialized products were found to be low-level task activities (consuming little work time). The average amount of time spent on the job per week was 42.7 hours with a mean of 20.4 hours spent in direct patient care, 13.6 hours in indirect patient care, and 7.3 hours in nonpatient care.

Dietary Services↗

PubMed1994

Hyperuricemia and insulin resistance.

The associates of gout-obesity, hypertriglyceridemia, glucose intolerance, and hypertension, strikingly resemble those of insulin resistance. In the present study we determined whether hyperuricemia is associated with insulin resistance and, if so, whether this association can be explained by other components of the syndrome. For this purpose we quantitated insulin sensitivity (euglycemic clamp) in 37 nondiabetic subjects (aged 30-68 yr) exhibiting varying degrees of the metabolic syndrome (body mass index, 21.5-35.7 kg/m2; serum triglycerides, 0.4-22.0 mmol/L; high density lipoprotein cholesterol 0.38-1.86 mmol/L; blood pressure, 190-100/116-60 mm Hg). In simple linear regression analysis, the serum uric acid concentration (range, 182-568 mumol/L) was inversely correlated with insulin sensitivity (rate of glucose utilization; r = -0.61; P < 0.001) and positively with serum triglycerides (r = 0.68; P < 0.001), but not with body mass index, age, or the plasma glucose concentration. In multiple linear regression analysis, both insulin sensitivity (P < 0.05) and serum triglycerides (P < 0.005) were independently associated with the serum uric acid concentration, and together explained 50% of its variation. Addition of body mass index or age to the model did not improve the degree of explanation. Acute elevation of serum triglycerides about 3-fold, of plasma FFA about 9-fold, or of serum insulin about 28-fold had no effect on the serum uric acid concentration in healthy volunteers. The data indicate that hyperuricemia is indeed an inherent component of the metabolic syndrome and could also be used as a simple marker of insulin resistance.

Adult↗

PubMed1983

Prediction of body volume by a stepwise linear regression technique.

Body volume and 35 anthropometric measurements were obtained from 88 active soldiers using standard techniques. These anthropometric measurements were examined for their possible relationships to body volume using stepwise linear regression analysis. Four measurements (Body weight, anterior thigh skinfold thickness, subscapular skinfold thickness and suprailiac skinfold thickness) accounted for 99.7% of the variation in body volume and the introduction of each of these measurements in the equation was significant. The regression equation for predicting body volume from these 4 anthropometric measurements had a multiple correlation coefficient of 0.9987 (P less than 0.001). Body weight alone was correlated with body volume to the extent of 0.9966. An attempt has therefore been made to develop a multiple linear regression equation without incorporation of body weight in the regression analysis. Nine measurements were selected by stepwise linear regression analysis for predicting body volume. These nine measurements accounted for 97.1% of the variation in body volume. These equations have been validated on another small sample of 22 soldiers. The analysis has also revealed that a direct regression of body density from the anthropometric variables gives more accurate results than when estimated body volumes are utilized for calculating body density.

Adolescent↗

PubMed1994

Interleukin-2 receptor levels in the sera of rheumatoid arthritis patients treated with methotrexate.

OBJECTIVE: To evaluate the association of the level of soluble serum interleukin-2 receptor (sIL-2R) with disease activity and response to therapy in patients with rheumatoid arthritis (RA). METHODS: The sIL-2R levels of 148 patients with refractory RA were determined by enzyme-linked immunosorbent assay. This parameter was correlated with other clinical observations obtained during a prospective, randomized, placebo-controlled trial of methotrexate, sponsored by the Cooperative Systematic Studies of Rheumatic Diseases consortium. Using statistical modeling, the usefulness of sIL-2R as a measure of disease activity and a predictor of outcome was evaluated. RESULTS: The mean sIL-2R level in all RA patients was markedly elevated compared with that in normal control subjects, and decreased significantly during the trial. There was no correlation of the sIL-2R level and the joint pain/tenderness count either at study entry or study end. There was a significant correlation of the sIL-2R level and the erythrocyte sedimentation rate, both at study entry and study end. A multiple linear regression model showed that treatment with methotrexate, but not the sIL-2R level or the change in sIL-2R level, predicted a change in joint count. A stepwise multiple logistic regression model defined no significant predictive information for outcome for the level of sIL-2R at study entry. CONCLUSION: After controlling for the simultaneous effects of other important clinical variables, the level of sIL-2R does not appear to predict the response to methotrexate in patients with refractory RA. Further analysis of cohorts of patients with earlier RA needs to be performed.

Adult↗

PubMed2004

Methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism is associated with osteoporotic vertebral fractures, but is a weak predictor of BMD.

Osteoporosis is a common disease with a strong genetic component. Linkage studies have suggested linkage between BMD and loci on chromosome 1. The MTHFR gene is located on chromosome 1. MTHFR catalyzes the conversion of 5,10-methylenetetrahydrofolate to 5-methylenetetrahydrofolate, which is used for homocysteine methylation to methionine. The rare genotype (TT) of the C677T polymorphism has previously been demonstrated to be associated with increased plasma homocysteine levels in individuals with inadequate plasma folate levels. Recently, the TT genotype has been found to be associated with reduced bone mass. We therefore examined if the C677T polymorphism in the MTHFR gene is associated with changes in bone mass and risk of osteoporotic fractures in 388 osteoporotic patients and 336 normal individuals. The distributions of the genotypes CC, CT and TT in women with osteoporotic vertebral fractures and normal controls were 43.5%, 42.2% and 14.3% and 52.0%, 42.0% and 8.0%, respectively, chi2 = 5.62, P = 0.06. Since studies of the functionality of this polymorphism have revealed that only the TT genotype is associated with biochemical changes, we also compared the prevalence of the TT genotype versus the CT- and CC genotypes in patients and controls and found that the TT genotype is significantly more common in women with vertebral fractures (14.3%) compared with normal controls (8.0%), chi2 = 4.31, P < 0.05. Logistic regression analysis demonstrated that vertebral fractures were significantly associated with BMD (lumbar spine) and height but only marginally with the MTHFR genotype (P = 0.06). Multiple linear regression analysis revealed that weight, age and the MTHFR polymorphism were predictors of lumbar spine BMD in women. However, age- and gender-corrected BMD of the lumbar spine and the hip was not significantly different between MTHFR genotypes. Furthermore, individuals with the TT genotype did not have BMD significantly lower than the combined group of individuals with the CT- or CC genotypes. In conclusion, we have demonstrated that the rare TT genotype of the C677T polymorphism in the MTHFR gene is associated with increased risk of osteoporotic fractures in women and a weak predictor of lumbar spine BMD.

Adult↗

PubMed2005

Large social disparities in spontaneous preterm birth rates in transitional Russia.

OBJECTIVE: This study estimated the effect of maternal sociodemographic, obstetric and lifestyle factors on the risk of spontaneous preterm birth in a Russian town. METHODS: All women with singleton pregnancies registered at prenatal care centres in Severodvinsk in 1999 comprised the cohort for this study (n=1559). Analysis was based on spontaneous live singleton births at the maternity home (n=1103). Multivariable logistic regression was applied to quantify the effect of the studied factors on the risk of preterm birth. Differences in gestation duration were studied using multiple linear regression. RESULTS: In total, 5.6% of all spontaneous births were preterm. Increased risks of preterm delivery were found in women with lower levels of education and in students. Placental complications, stress and a history of fetal death in previous pregnancies were also associated with elevated risks for preterm delivery. Smoking, hypertension and multigravidity were associated with reduced length of pregnancy in metric form. CONCLUSION: In addition to medical risk factors, social factors are important determinants of preterm birth in transitional Russia. Large disparities in preterm birth rates may reflect the level of inequalities in transitional Russia. Social variations in pregnancy outcomes should be monitored.

Adolescent↗

PubMed2003

Rate of progression of glaucoma correlates with retrobulbar circulation and intraocular pressure.

PURPOSE: To evaluate the correlation between progression rate of glaucomatous damage and retrobulbar blood flow in an institutional setting. DESIGN: Retrospective, observational case series. METHODS: Twenty open-angle glaucoma patients with at least five visual field examinations and progressive damage in at least one eye were included in the study. Mean +/- standard deviation follow-up time was 4.3 +/- 1.6 years. As an indicator of progression rate of visual field damage, the angle to a horizontal line of the slope of the regression line of the visual field index mean defect over time was calculated for one randomly selected eye per patient. The association between this angle and intraocular pressure, as well as retrobulbar color Doppler imaging measurements obtained at the beginning of the observation period, was analyzed by a multiple linear regression analysis in a stepwise forward approach. RESULTS: With a faster rate in progression of glaucomatous damage, a lower baseline end diastolic blood flow velocity in the central retinal artery (partial r = -.63; P <.0037) and a higher baseline intraocular pressure (partial r =.59; P <.0078) were noted (multiple r =.69; P <.0043). Rate of progression was not related to the extent of preexisting visual field damage. CONCLUSIONS: Independent of the extent of glaucomatous damage and intraocular pressure, the progression rate of glaucomatous visual field damage statistically correlates with retrobulbar hemodynamic variables.

Antihypertensive Agents↗

PubMed2004

The common PPAR-gamma2 Pro12Ala variant is associated with greater insulin sensitivity.

Several genetic variants of peroxisome proliferator-activated receptor-gamma2 (PPAR-gamma2) have been identified, among which Pro12Ala, a missense mutation in exon 2, is highly prevalent in Caucasian populations. Up to now, conflicting results with regard to the association between this mutation and complex traits, such as obesity, insulin sensitivity and Type 2 diabetes, have been reported. We investigated the influence of the Pro12Ala polymorphism of PPAR-gamma2 on insulin sensitivity in a large Italian population sample, n=1215, in whom extensive clinical and biochemical analyses were performed. To estimate the insulin sensitivity status, the homeostasis model assessment of insulin resistance (HOMA-IR) was calculated; in the obese/overweight subjects an oral glucose tolerance test (OGTT) was also performed and the Matsuda insulin sensitivity index (ISI) calculated. The insulin secretion index (homeostasis model assessment of percent beta-cell function, HOMA-beta%) was utilized to evaluate beta-cell function. The effect of the Pro12Ala polymorphism on quantitative variables was tested using multiple linear regression analysis. X12Ala (either Pro12Ala or Ala12Ala) genotype was associated with significantly lower fasting insulin levels compared to Pro/Pro (P=0.01 after correction for multiple comparisons) in all subjects. Consistent with this finding, significantly lower HOMA-IR was observed in X12Ala carriers (P=0.013 after correction for multiple comparisons) in all cohort. Moreover, no significant interaction effect was observed between body mass index and X12Ala polymorphism and between gender and X12Ala polymorphism in modulating insulin sensitivity. Our observations substantially extend previous findings and demonstrated that X12Ala variant is significantly associated with greater insulin sensitivity.

Amino Acid Substitution↗