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X Formiguera

Publications and source records attributed to X Formiguera.

9 recordsLinked to original sources
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↗