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Biomedical subjects

X Formiguera

Publications and source records attributed to X Formiguera.

At least 19 recordsLinked to original sources
PubMed2006

The effect of bariatric surgery on adipocytokines, renal parameters and other cardiovascular risk factors in severe and very severe obesity: 1-year follow-up.

AIMS: To evaluate the effect of weight loss after bariatric surgery (BS) on peripheral adipocytokines, renal parameters and other cardiovascular risk factors (CVRFs). METHODS: A total of 70 (41 women) extremely obese adults were prospectively studied before and 12 months after surgery. CONTROLS: 24 (15 women) normal-weight adults. Anthropometric, biochemical and renal parameters were recorded. RESULTS: Presurgery, adiponectin (ADPN) was lower, whereas leptin, insulin resistance, C-reactive protein, creatinine clearance and albuminuria were higher in patients than controls (P<0.001). All parameters improved postsurgery. Changes in ADPN correlated negatively with leptin, insulin resistance, albumin, C-reactive protein, and creatinine clearance. Multiple regression analysis: using changes in ADPN as the dependent variable, only changes in insulin resistance (P=0.005) and albumin (P=0.019) were significant independent determinants for changes in ADPN. No statistical differences were found in relation to the degree of obesity. CONCLUSION: Patients changed to obesity type I after surgery. This implies a substantial improvement of CVRFs including ADPN, creatinine clearance and albuminuria. Changes in plasma ADPN correlated negatively with insulin resistance and with albuminemia but not with renal parameters. The lack of differences between different degrees of obesity suggests that the relationship between weight and CVRFs no longer exists when obesity becomes very extreme.

Adiponectin↗
PubMed2001

[Hormonal alterations on young morbid obese women].

BACKGROUND: Human obesity is a widespread disease with considerable variability as to its severity, metabolic and endocrine manifestations and etiology. In the present study we have determined whether the alterations of uncomplicated severe obesity in adult young women affect with different intensity the circulating levels of hormones that have been postulated to intervene in the development and maintenance of obesity. SUBJECTS AND METHOD: Age-matched 20 morbidly obese (BMI 52.6 [8.3 SD] kg/m2) and 10 normal-weight control women (BMI 19.9 [2.1 SD] kg/m2)were studied and determined the basal circulating levels of hormones and proteins related with the control of body weight. RESULTS: Obese women showed higher concentrations of insulin and leptin, and lower of cortisol and cortisol-binding globulin (CBG). No significant differences were appreciated for free thyroxine, TSH, free and acylestrone and dehydroepiandrosterone-sulphate. CONCLUSIONS: The results suggest that morbid obesity implies the alteration of the main hormonal systems controlling the availability of energy and the response to external challenges, with the noteworthy exception of the thyroid. There were clear alterations of insulin and leptin,but cortisol changes could be more related to factors other than obesity. The lower than expected levels of acylestrone point to a possible deficit of this ponderostat signal in obese women. The relatively young age of the women in the study may account for the relative shallowness of the hormonal changes observed.

Adult↗
PubMed2001

Short-term effects of a hypocaloric diet on nitrogen excretion in morbid obese women.

OBJECTIVE: To determine whether the daily pattern of urine excretion of N wastes is affected by obesity and very low-calorie diets (VLCD). DESIGN: The plasma amino acid, urea and other energy parameters, as well as the urinary excretion of total nitrogen, urea and creatinine were studied in obese and normal-weight women. The obese women's data were obtained under hospital basal controlled conditions (8.1 MJ/day) and after 3 days of VLCD diet (1.9 MJ/day) controls were studied only once (5.8 MJ/day). The hourly excretion patterns of total N, urea and creatinine were determined from the composition of each bladder voiding. SUBJECTS: Twenty morbidly obese and 10 age-matched normal-weight control women. RESULTS: Plasma amino acid levels were higher in obese women, which showed a limited ability to metabolize amino acid hydrocarbon skeletons. Neither differences in the patterns between groups nor total 24 h values for urine volume were found. Total N and urea excretion diminished under VLCD diet. Hourly creatinine excretion showed a flat pattern and was higher in obese women than in the controls, VLCD diet diminished the amount of creatinine excreted in 24 h. CONCLUSIONS: The early change in energy availability that the creatinine excretion figures reflect may result from the energy conservation mechanisms induced in response to energy restriction. The early onset of this effect (3 days, and the extent of decrease (approximately 19%) also suggest that the impact of VLCD on the muscle energy budget of the obese is more marked than usually assumed.

Adult↗
PubMed2000

Randomized controlled trial of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates on body weight and blood lipids: the CARMEN study. The Carbohydrate Ratio Management in European National diets.

OBJECTIVE: To investigate the long-term effects of changes in dietary carbohydrate/fat ratio and simple vs complex carbohydrates. DESIGN: Randomized controlled multicentre trial (CARMEN), in which subjects were allocated for 6 months either to a seasonal control group (no intervention) or to one of three experimental groups: a control diet group (dietary intervention typical of the average national intake); a low-fat high simple carbohydrate group; or a low-fat high complex carbohydrate group. SUBJECTS: Three hundred and ninety eight moderately obese adults. MEASUREMENTS: The change in body weight was the primary outcome; changes in body composition and blood lipids were secondary outcomes. RESULTS: Body weight loss in the low-fat high simple carbohydrate and low-fat high complex carbohydrate groups was 0.9 kg (P < 0.05) and 1.8 kg (P < 0.001), while the control diet and seasonal control groups gained weight (0.8 and 0.1 kg, NS). Fat mass changed by -1.3kg (P< 0.01), -1.8kg (P< 0.001) and +0.6kg (NS) in the low-fat high simple carbohydrate, low-fat high complex carbohydrate and control diet groups, respectively. Changes in blood lipids did not differ significantly between the dietary treatment groups. CONCLUSION: Our findings suggest that reduction of fat intake results in a modest but significant reduction in body weight and body fatness. The concomitant increase in either simple or complex carbohydrates did not indicate significant differences in weight change. No adverse effects on blood lipids were observed. These findings underline the importance of this dietary change and its potential impact on the public health implications of obesity.

Adult↗
PubMed2000

Wernicke's syndrome after bariatric surgery.

Two young females with severe morbid obesity presented with Wernicke's syndrome after Roux-en-Y gastro-jejunum bypass had been performed. The first patient had recurrent vomiting and dyplopia two months post-surgery. Physical examination indicated bilateral ophthalmoparesia with conserved convergence and ataxia. The second patient had frequent vomiting episodes over the previous three months together with lower limb hypotonia, myoclonia and generalised tonicoclonic seizures on two occasions within one year of surgery. In both cases routine blood test, ion levels (sodium, potassium, calcium, phosphates), electroencephalogram and CT scan were normal. Thiamine therapy was instigated on the basis of clinical intuition and the first patient achieved complete remission within 24 hours while the second improved gradually in that two years later only mild lower limb hypotonia and a slight cognitive deficit remains. Erythrocyte transketolase activity determinations were abnormal on two separate occasions for this second patient. Vitamin B1 determinations were not available for the first patient. In conclusion, the restriction in energy intake and the persistent vomiting together with malabsorption induced by the surgical intervention could explain the vitamin deficiency causing Wernicke's encephalopathy. This indicates a need for close monitoring and systematic vitamin supplementation in those patients who undergo bariatric surgery.

Adult↗
PubMed1998

Band erosion in patients who have undergone vertical banded gastroplasty: incidence and technical solutions.

OBJECTIVES: To study the incidence of band erosion in patients who have undergone vertical banded gastroplasty and to describe the reparative techniques used. DESIGN: A retrospective review case series. SETTING: A university hospital-based tertiary referral center. PATIENTS: Two hundred fifty consecutive morbidly obese patients who underwent vertical banded gastroplasty between 1987 and 1995. MAIN OUTCOME MEASURES: The development of band erosion into the stomach, reparative surgical techniques, and long-term weight loss control. RESULTS: Band erosion developed in 7 (2.8%) of the patients. Two patients had symptoms 1 month after undergoing forced endoscopy. Six patients required reoperation. The operative findings included 2 cases of "external" band erosion through the lesser curvature into the stomach and 4 cases of "internal" band erosion through the circular staple line. The surgical techniques used for repair depended on the radiological and endoscopic data and on the operative findings; the techniques included conversion into a gastric bypass, band replacement after the creation of a new stoma, and gastroplasty plus distal gastric bypass. There were no complications, and adequate long-term weight loss was achieved in all but 1 of the patients who underwent reoperation. CONCLUSION: Band erosion may be corrected using appropriate surgical techniques to allow for adequate long-term weight loss in patients who have undergone vertical banded gastroplasty.

Adult↗
PubMed1998

Increased leptin production in vivo and insulin cleavage by the omental adipose tissue of morbidly obese patients.

OBJECTIVE: The aim of this investigation was to assess the insulin cleavage capacity in obese humans. Increased insulin degradation by visceral adipose tissue has previously been demonstrated in obese rats and could be interpreted as a physiological response to hyperinsulinaemia. The recent characterization of leptin receptors in pancreatic beta cells, liver and muscle suggests that leptin may influence insulin function and metabolism. Our study focuses on the possible relationship between leptin secretion and adipose tissue insulin-degrading capacity. DESIGN AND PATIENTS: Insulin and leptin were measured in arterial blood and in the epiploic vein of morbidly obese (n = 7) and non-obese patients (n = 7) who were undergoing abdominal surgery. Arteriovenous insulin difference (AV insulin) was considered an in vivo marker of insulin degradation by the omental fat tissue. Statistical comparison between venous and arterial leptin was used to assess endogenous leptin production. MEASUREMENTS: Insulin was measured using an oligoclonal IRMA and leptin levels were determined by using a specific radioimmunoassay. RESULTS: Morbidly obese patients were hyperinsulinaemic compared to non-obese patients according to arterial insulin levels (P = 0.049) but not to venous levels. Insulin cleavage capacity, nil in the control group, was clearly significant in the morbidly obese patients (P = 0.001). In the morbidly obese group, leptin levels in venous epiploic samples were significantly higher (P = 0.028) than in the arterial samples, confirming in situ the synthesis of leptin by human white adipose tissue. We also observed a correlation between insulin arterial levels and venous leptin concentrations (P = 0.009) which supports the chronic leptinogenic effect of insulin suggested in previous works. Finally, our results show that venous leptin levels are correlated with the extent of insulin cleavage by omental tissue (P = 0.033). CONCLUSIONS: Morbidly obese patients have a higher white adipose tissue insulin cleavage capacity, which could partially diminish hyperinsulinaemia-derived adverse effects. High leptin production, a consequence of high insulin levels, may act as a signal to the insulin-degrading tissues in order to lower insulinaemia.

Adipose Tissue↗
PubMed1998

Growth hormone-binding protein directly depends on serum leptin levels in adults with different nutritional status.

The aim of this work was to assess the relationship between GH-binding protein (GHBP) and leptin. Both peptides are nutritionally regulated, but the recent implication of a role for leptin in the GH axis requires further study. To avoid the sexual dimorphism in leptin values, we performed leptin standardization according to gender (SD score-leptin). The relationship between SD score-leptin and GHBP was studied in 128 adults with different nutritional status [8 groups according to body mass index (BMI)], ranging from severely underweight anorexia nervosa to highly morbid obesity. Both GHBP and SD score-leptin significantly increased according to BMI within the range from 18-27 kg/m2, whereas no significant differences were found among underweight groups (BMI, < 18 kg/m2) or among obesity grades (BMI, > 27 kg/m2). We found a strong correlation between GHBP and SD score-leptin (r = 0.8; P < 0.0001). Multiple regression analysis revealed SD score-leptin to be a significant determinant of GHBP, accounting for 64% of the variation, whereas BMI did not contribute further to explaining changes in GHBP. This suggests a physiological pathway involving both GHBP (the soluble fraction of GH receptor) and leptin. Thus, we might speculate that leptin could be the signal that induces the related nutritional changes observed in GHBP/GH receptor expression.

Adolescent↗
PubMed1997

Analytical performance and clinical usefulness of two binding assays for growth hormone binding protein (GHBP) measurement: high performance liquid chromatography (HPLC)-gel filtration and dextran-coated charcoal adsorption.

We compared two binding assays for growth hormone binding protein (GHBP) measurements, which differ in the method of bound and free GH separation: HPLC-gel filtration or dextran coated-charcoal adsorption (DCC). Two pools of sera (high and medium GHBP activity) were used for quality-control assessment. Moreover, 62 samples from 34 children and 28 adults with different nutritional status were studied. Total, between- and intra-iodination coefficients of variation (CVs) from the two methods were not different. Although percentage binding measured in the pool sera significantly differed, the concentrations assessed by Scatchard plot were comparable. Results obtained by the two methods in the 62 sera were significantly correlated (r = 0.77, P < 0.001). With both methods GHBP activity correlated with chronological age and body mass index (BMI) and differed among groups with different nutritional status. Although HPLC and DCC separation methods for GHBP measurement differ in their practicability, our study demonstrates that performance and the clinical usefulness of the two methods are comparable.

Adolescent↗
PubMed1995

Insulin degradation by adipose tissue is increased in human obesity.

White adipose tissue samples from obese and lean patients were used for the estimation of insulin protease and insulin:glutathione transhydrogenase using 125I-labeled insulin. There was no activity detected in the absence of reduced glutathione, which indicates that insulin is cleaved in human adipose tissue through reduction of the disulfide bridge between the chains. Obese patients showed higher transhydrogenase activity (per U tissue protein wt, per U tissue wt, and in the total adipose tissue mass) than the lean group. There is a significant correlation between the activity per U tissue wt, and protein and total activity in the whole adipose tissue with respect to body mass index, with a higher activity in obese patients. The potential of insulin cleavage by adipose tissue in obese patients was a mean 5.6-fold higher than that in controls. The coexistence of high insulinemia and high cleavage capability implies that insulin secretion and turnover are increased in the obese. Thus, white adipose tissue may be crucial in the control of energy availability through modulation of insulin cleavage.

Adipose Tissue↗
PubMed1991

Effect of obesity on gastroesophageal resistance to flow in man.

Chronic (obesity) and acute intraabdominal pressure increases appear to favor gastroesophageal reflux, but the mechanism is not completely understood. We hypothesized that it could be due to an alteration in the resistance gradient between the stomach and the gastroesophageal junction, even increasing intragastric resistance above resistance at the gastroesophageal junction. Hence, we used a pneumatic resistometer to measure gastric and gastroesophageal resistance to flow in 11 lean healthy controls and eight morbidly obese individuals without gastroesophageal reflux disease. Resistance was quantified at rest and during acute intraabdominal pressure increases, both in the recumbent and sitting positions. We found that gastroesophageal junction resistance was higher than gastric resistance in lean as well as in obese subjects (P less than 0.001). In obese individuals both gastric and gastroesophageal junction resistance were increased (P less than 0.001), thus a normal gastric-gastroesophageal junction resistance gradient was maintained. Body position did not modify resistance. Acute increases in intraabdominal pressure decreased the gastric-gastroesophageal junction resistance gradient similarly in obese and lean subjects. We conclude that obesity by itself does not appear to predispose to gastroesophageal reflux, but it creates intraabdominal conditions that may favor reflux whenever the gastroesophageal barrier becomes weakened.

Adult↗
PubMed1991

Postural variation of the maximum inspiratory and expiratory pressures in obese patients.

Evaluating whether weight is a factor responsible for the decrease of muscle force in the supine position with respect to the upright and sitting positions, we measured maximum inspiratory and expiratory pressures (PImax and PEmax) in these postures in ten obese patients (age 38.7 +/- 9.1 years; height 168.7 +/- 8.9 cm; and weight 139.3 +/- 28.4 kg) and ten normal control subjects (age 38.4 +/- 8.2 years; height 169.3 +/- 7.9 cm and weight 66.9 +/- 11.9 kg.) In both study groups, PImax and PEmax values decreased in the supine posture with respect to upright and sitting positions. Differences between pressures in the various postures were similar for both groups with the exception of PEmax in obese females. The decrease in PEmax values from the sitting to supine positions was greater in obese than control females. Weight, sex and postural changes can influence the generation of maximal expiratory force.

Adult↗