Impact of carbohydrate and fat intake on weight-reducing efficacy of Orlistat ( Xenical ).

BACKGROUND: Orlistat ( Xenical ) treatment of obesity results in a poor long-term weight loss (< 5%) in about 30% of patients. AIM: Total energy and macronutrient intake were examined to assess the effect of a change in eating habits on weight loss. METHODS: Sixty-two patients consumed a hypocaloric diet, together with Orlistat ( Xenical ) (3 x 120 mg/day), for 72 weeks, with a maximal fat allowance of 30% of the energy intake. At regular intervals, food diaries were recorded. RESULTS: Fifty-six patients completed the study and lost 8.5 +/- 0.88 kg (P < 0.001). Energy intake was approximately 1500 kcal/day during the entire study period. In three sub-groups established according to weight loss (1, < 5%; 2, > 5% and < 10%; 3, > 10%), fat intake was within the recommended range in all groups during the first 6 months, but thereafter only in group 3. All groups increased their carbohydrate consumption, with the greatest increase in group 1, which could account for the rapid regain of initially lost body weight in this group. CONCLUSION: At the beginning of a weight management programme in conjunction with Orlistat ( Xenical ), a low fat intake is advised for an efficient reduction in body weight. Subsequently, in patients with poor long-term weight loss, dietary recommendations must also consider carbohydrate restriction to ensure an adequate hypocaloric diet.

Orlistat ( Xenical ) is as beneficial as metformin in the treatment of polycystic ovarian syndrome.

The objective of this study was to evaluate and compare the effect of treatment with Orlistat ( Xenical ) vs. metformin on the hormonal and biochemical features of patients with polycystic ovarian syndrome (PCOS). Twenty-one Caucasian women with PCOS [mean (+/-SEM) age 27 +/- 0.9 yr and body mass index 36.7 +/- 3.3 kg/m(2)] participated in this prospective, randomized, open-labeled study. All subjects had an 8-wk run-in period of dietary modification and then randomized to receive either metformin (500 mg three times daily) or Orlistat ( Xenical ) (120 mg three times daily) for 3 months. Weight, blood pressure, and fasting blood samples were taken at screening, randomization, and on completion. Insulin resistance (IR) was calculated using the homeostasis model of assessment (HOMA)-IR method [HOMA-IR = (insulin x glucose)/22.5]. The results are expressed as mean +/- SEM. When compared with baseline, treatment with both Orlistat ( Xenical ) [93.5 +/- 11.5 ng/dl (3.24 +/- 0.4 nmol/liter) vs. 114.5 +/- 11.5 ng/dl (3.97 +/- 0.4 nmol/liter), P = 0.039] and metformin [97.2 +/- 11.5 ng/dl (3.37 +/- 0.4 nmol/liter) vs. 120.0 +/- 8.7 ng/dl (4.16 +/- 0.3 nmol/liter), P = 0.048] produced a significant reduction in total testosterone. Treatment with Orlistat ( Xenical ) produced a 4.69% reduction in weight (99.0 +/- 6.0 vs. 94.6 +/- 6.1 kg, P = 0.002), and this reduction was more significant than the reduction produced by metformin (4.69 vs. 1.02%, P = 0.006). There was no significant reduction seen after either treatment group for fasting insulin, HOMA-IR, SHBG, or any of the lipid parameters studied. In this study, Orlistat ( Xenical ) produced a significant reduction in weight and total testosterone. The reduction in total testosterone was similar to that seen after treatment with metformin. Therefore, Orlistat ( Xenical ) may prove to be a useful adjunct in the treatment of PCOS.

Natural abundance 13C-NMR spectroscopy for the quantitative determination of fecal fat.

OBJECTIVE: To evaluate 13C-NMR spectroscopy as a method for fat quantitation in human feces without time consuming or unpleasant preparation steps. DESIGN AND METHODS: Stool samples of seven healthy subjects were collected for 18 days before and during oral intake of the inhibitor of gastrointestinal lipases Orlistat ( Xenical ). Fecal lipid content was determined first using 13C-NMR, then by conventional gravimetry after homogenization and Bligh & Dyer lipid extraction. RESULTS: The correlation between gravimetry and 13C-NMR was excellent (R2 = 0.91). In repeated measurements, the mean percentage error was 2.8%. On average, 13C-NMR yielded 1.27 g less fat than gravimetry. Orlistat ( Xenical ) efficacy for fat excretion assessed by 13C-NMR and by gravimetry was 34.3% and 33.9%, respectively. CONCLUSIONS: With a total measurement time of three minutes, 13C-NMR spectroscopy of unprocessed whole stool provides an accurate alternative to gravimetry for assessing total fecal fat excretion. 13C-NMR is superior with regard to practicability and speed.

Fat malabsorption induced by gastrointestinal lipase inhibitor leads to an increase in urinary oxalate excretion.

BACKGROUND: Unabsorbed fat and bile acids may react with calcium in the intestinal lumen, limiting the amount of free calcium binding with oxalate and thereby raising intestinal oxalate absorption leading to hyperoxaluria. The aim of the present study was to determine whether Orlistat ( Xenical ) , a gastrointestinal lipase inhibitor, might increase urinary oxalate in an experimental rat model. METHODS: Thirty-nine male adult Wistar rats were fed a standard diet alone (controls) or supplemented with either 2% sodium oxalate (NaOx) or 3.2 mL of soy oil, or with both (NaOx + soy oil) for 4 weeks (diet period). Orlistat ( Xenical ) (16 mg/day) was added to the diet from the 5th to the 8th week (diet + Orlistat ( Xenical ) period). Urinary oxalate (uOx), calcium (uCa), magnesium (uMg), and citrate (uCit) were determined and the ion-activity product of calcium oxalate [AP (CaOx) index(rat)] was estimated. RESULTS: Compared to baseline uOx significantly increased after diet + Orlistat ( Xenical ) in controls (0.64 +/- 0.1 mg/24 hours vs. 0.56 +/-0.1 mg/24 hours), soy oil (0.80 +/- 0.3 mg/24 hours vs. 0.49 +/-0.2 mg/24 hours), and NaOx (2.48 +/- 0.8 mg/24 hours vs. 0.57 +/- 0.2 mg/24 hours), but the most marked increase occurred in NaOx + soy oil (3.87 +/- 0.7 mg/24 hours vs. 0.47 +/- 0.1 mg/24 hours). All groups except controls presented a significant reduction in uCa and uMg. Orlistat ( Xenical ) induced a significant increase in AP (CaOx) index(rat) compared, respectively, to baseline and to the diet period in NaOx (4.52 +/- 2.34 mg/24 hours vs. 0.94 +/- 0.86 and 1.53 +/- 0.93 mg/24 hours) and NaOx + soy oil (6.49 +/- 4.03 mg/24 hours vs. 0.54 +/- 0.17 and 1.76 +/- 1.32 mg/24 hours). CONCLUSION: These data suggest that the use of lipase inhibitors, especially under a diet rich in oxalate alone or associated with fat, leads to a significant and marked increase in urinary oxalate and a slight reduction in uCa and uMg that, taken together, resulted in an increase in AP (CaOx) index(rat), elevating the risk of stone formation.