Fasting state is one of the factors associated with plasma levodopa fluctuations during levodopa‒carbidopa intestinal gel treatment.

INTRODUCTION: Some patients with Parkinson's disease (PD) undergoing levodopa‒carbidopa intestinal gel (LCIG) treatment experience motor fluctuations in the afternoon. The migrating motor complex, a specific periodic migrating contraction pattern occurring in the stomach and small intestine during the fasting state, can affect drug absorption. We aimed to compare the pharmacokinetic parameters between two conditions (with and without lunch) and assessed the influence of the fasting state on the levodopa pharmacokinetics in LCIG treatment. METHODS: We evaluated the levodopa pharmacokinetics from 12:00 p.m. to 6:00 p.m. in 10 LCIG-treated PD patients in the presence and absence of lunch. RESULTS: The maintenance dose of LCIG correlated strongly with the mean plasma concentration of levodopa in the absence (r = 0.94, coefficient of determination (R2) = 0.89, p < 0.001) or presence of lunch (r = 0.96, R2 = 0.93, p < 0.001). Comparison of the pharmacokinetic parameters revealed that the coefficient of variation was significantly greater in the condition without lunch than in the condition with lunch (p = 0.004): 16.73% (4.88%) without lunch and 9.22% (3.80%) with lunch. There were no significant differences in the mean plasma concentration of levodopa (p = 0.49) and area under the plasma concentration‒time curve (p = 0.27) between the two conditions. CONCLUSIONS: Plasma concentrations of levodopa fluctuated more in patients undergoing LCIG treatment without than with lunch. Our results indicate that a small amount of food intake may be a better corrective approach for worsening of symptoms in the fasting state rather than additional levodopa.

Whey Protein Drink Ingestion before Breakfast Suppressed Energy Intake at Breakfast and Lunch, but Not during Dinner, and Was Less Suppressed in Healthy Older than Younger Men.

Ageing is associated with changes in feeding behavior. We have reported that there is suppression of energy intake three hours after whey protein drink ingestion in young, but not older, men. This study aimed to determine these effects over a time period of 9 h. Fifteen younger (27 ± 1 years, 25.8 ± 0.7 kg/m2) and 15 older (75 ± 2 years, 26.6 ± 0.8 kg/m2) healthy men were studied on three occasions on which they received, in a randomized order, a 30 g/120 kcal, 70 g/280 kcal whey-protein, or control (~2 kcal) drink. Ad-libitum energy intake (sum of breakfast, lunch, and dinner) was suppressed in a protein load responsive fashion (P = 0.001). Suppression was minimal at breakfast, substantial at lunch (~-16%, P = 0.001), no longer present by dinner, and was less in older than younger men (-3 ± 4% vs. -8 ± 4%, P = 0.027). Cumulative protein intake was increased in the younger and older men (+20% and +42%, P < 0.001). Visual analogue scale ratings of fullness were higher and desire to eat and prospective food consumption were lower after protein vs. control, and these effects were smaller in older vs. younger men (interaction effect P < 0.05). These findings support the use of whey-protein drink supplements in older people who aim to increase their protein intake without decreasing their overall energy intake.

Perceived thickness and creaminess modulates the short-term satiating effects of high-protein drinks.

Previous research suggests that increasing beverage protein content enhances subsequent satiety, but whether this effect is entirely attributable to post-ingestive effects of protein or is partly caused by the distinct sensory characteristics imparted by the presence of protein remains unclear. To try and discriminate nutritive from sensory effects of added protein, we contrasted effects of three higher-energy (about 1·2 MJ) and one lower-energy (LE: 0·35 MJ) drink preloads on subsequent appetite and lunch intake. Two higher-energy drinks had 44% of energy from protein, one with the sensory characteristics of a juice drink (HP2, low-sensory protein) and the second a thicker and creamier (HPþ, high-sensory protein) drink. The high-carbohydrate preload (HCþ, high-sensory carbohydrate) was matched for thickness and creaminess to the HPþ drink. Participants (healthy male volunteers, n 26) consumed significantly less at lunch after the HPþ(566 g) and HCþ(572 g) than after HP2 (623 g) and LE (668 g) drinks, although the compensation for drink energy accounted for only 50% of extra energy at best. Appetite ratings indicated that participants felt significantly less hungry and more full immediately before lunch in HPþ and HCþ groups compared with LE, with HP2 being intermediate. The finding that protein generated stronger satiety in the context of a thicker creamier drink (HPþ but not HP2) and that an isoenergetic carbohydrate drink (HCþ), matched in thickness and creaminess to the HPþ drink, generated the same pattern of satiety as HPþ, both suggest an important role for these sensory cues in the development of protein-based satiety.