Search PubMed⌕ Search

Biomedical subjects

K Renquist

Publications and source records attributed to K Renquist.

7 recordsLinked to original sources
PubMed1994

A Study on Predicting Weight Loss Following Surgical Treatment for Obesity.

To date, longitudinal weight loss analyses (curve-fitting) have been complicated by non-linear weight patterns, incomplete follow-up, and varied follow-up times. Therefore, the cross-sectional design (one time point survey) was chosen to study predictors of weight loss at yearly postoperative time intervals (+/- 6 months). Mean values for the initial cohort of 7,540 patients were: age 37.4 years (+/- 9.4), weight 124.0 kg (+/- 25.5), height 165.4 cm (+/- 8.5). Females comprised 87.7% of the data set. Follow-up was 62.5% at year one, 32.0% at year 2, 20.6% at year 3, and 15.4% at year 4. The multiple regression model used included 20 explanatory variables and was performed separately for four yearly time points. Only operative weight, initial visit height, age, and operative type were consistent predictors of weight loss (p < 0.05) at all time points examined and accounted for 40-50% of weight loss variation.

Journal Article↗
PubMed1992

Calculating Follow-up Rates.

Follow-up rates are presented as a percentage but the method of calculation is seldom discussed. Determining a follow-up rate begins with identifying the numerator and denominator used in the calculation. Four methods of calculating follow-up rate after surgical treatment for weight reduction were studied. Method 1 follow-up rate, 91.2%, was calculated using patients with at least one follow-up contact as the numerator (6169) and the number of primary operations performed as the denominator (6764). Method 2 calculated patient contact on or beyond a specific time point: 65.9% for >/= 6 months (4232/6424), >/= 1 year (y) = 52.1% (3111/5977), >/= 2 y = 29.8% (1455/ 4890), >/=3y=18.8% (710/3784), >/=4y=12.5% (331/ 2643). Follow-up calculated using method 3 determined patient contact within specific time points: 0-1 y = 89.7% (6064/6764), 1-2 y = 45.8% (2739/5977), 2-3 y = 23.0% (1124/4890), 3-4 y=13.9% (526/3784), 4-5y=11.3% (298/2643). Method 4 studied patient contact within time points according to ASBS guidelines. Rates for method 4 were: 0-6 months = 58.8% (11,938/20,292), 6-12 months = 36.7% (4717/12,848), 1-2 y = 45.8% (2739/5977), 2-3 y = 23.0% (1124/4890), 3-4 y = 13.9% (52613784). Results using these four methods of calculation emphasize the need to standardize follow-up rate before operative comparisons can be made.

Journal Article↗
PubMed1992

Predictors of Two Obesity Complications: diabetes and hypertension.

Gender, age, waist-hip ratio (WHR) and body mass index (BMI) have been reported to herald two complications of obesity: diabetes or hypertension. Most literature is based on patient populations with mean BMIs ranging from 22 to 35 kg/m(2). This study population of severely obese patients selected for surgical treatment of obesity had a mean age of 37 +/- 9.4 years, median WHR of 0.9 (0.4-2.1) and median BMI of 44.0 (29-89) kg/m(2). It was found that age, WHR and BMI were significant predictors for diabetes or hypertension. Gender was not found to be a significant predictor for either diabetes or hypertension. A mathematical model was used to calculate the predictive probability of developing diabetes or hypertension using age, BMI and WHR.

Journal Article↗
PubMed1987

Ion transport in human cecum, transverse colon, and sigmoid colon in vitro. Baseline and response to electrical stimulation of intrinsic nerves.

In a flux chamber study of ion transport in human colon, we compared baseline rates with those measured during electrical stimulation of intrinsic nerves. In baseline studies, sodium was absorbed throughout, but maximally in transverse colon. In cecum, sodium absorption accounted for the short circuit current and chloride was not absorbed. Chloride was absorbed in transverse and sigmoid colon, however. Residual current was minimal in cecum and transverse colon, but increased in sigmoid colon. Neural stimulation caused chloride secretion in cecum, reduced chloride absorption in sigmoid colon, but caused no change in transverse colon; sodium absorption decreased in cecum. A neurotransmitter of unknown identity affects baseline short circuit current in sigmoid colon. Half of the increase in short circuit caused by neural stimulation in sigmoid colon is mediated by muscarinic receptors. The identity of the other transmitter(s) is not known. It is not substance P or histamine. The three divisions of the colon differ in relative rates of baseline ion transport and in their transport responses to intrinsic nerve stimulation.

Cecum↗