Increasing the protein quantity in a meal results in dose-dependent effects on postprandial glucose levels in individuals with Type 1 diabetes mellitus.

AIM: To determine the glycaemic impact of increasing protein quantities when consumed with consistent amounts of carbohydrate in individuals with Type 1 diabetes on intensive insulin therapy. METHODS: Participants with Type 1 diabetes [aged 10-40 years, HbA1c ≤ 64 mmol/mol (8%), BMI ≤ 91st percentile] received a 30-g carbohydrate (negligible fat) test drink daily over 5 days in randomized order. Protein (whey isolate 0 g/kg carbohydrate, 0 g/kg lipid) was added in amounts of 0 (control), 12.5, 25, 50 and 75 g. A standardized dose of insulin was given for the carbohydrate. Postprandial glycaemia was assessed by 5 h of continuous glucose monitoring. RESULTS: Data were collected from 27 participants (15 male). A dose-response relationship was found with increasing amount of protein. A significant negative relationship between protein dose and mean excursion was seen at the 30- and 60-min time points (P = 0.007 and P = 0.002, respectively). No significant relationship was seen at the 90- and 120-min time points. Thereafter, the dose-response relationship inverted, such that there was a significant positive relationship for each of the 150-300-min time points (P < 0.004). Mean glycaemic excursions were significantly greater for all protein-added test drinks from 150 to 300 min (P < 0.005) with the 75-g protein load, resulting in a mean excursion that was 5 mmol/l higher when compared with the control test drink (P < 0.001). CONCLUSIONS: Increasing protein quantity in a low-fat meal containing consistent amounts of carbohydrate decreases glucose excursions in the early (0-60-min) postprandial period and then increases in the later postprandial period in a dose-dependent manner.

Influence of dietary protein on postprandial blood glucose levels in individuals with Type 1 diabetes mellitus using intensive insulin therapy.

AIM: To determine the effects of protein alone (independent of fat and carbohydrate) on postprandial glycaemia in individuals with Type 1 diabetes mellitus using intensive insulin therapy. METHODS: Participants with Type 1 diabetes mellitus aged 7-40 years consumed six 150 ml whey isolate protein drinks [0 g (control), 12.5, 25, 50, 75 and 100] and two 150 ml glucose drinks (10 and 20 g) without insulin, in randomized order over 8 days, 4 h after the evening meal. Continuous glucose monitoring was used to assess postprandial glycaemia. RESULTS: Data were collected from 27 participants. Protein loads of 12.5 and 50 g did not result in significant postprandial glycaemic excursions compared with control (water) throughout the 300 min study period (P > 0.05). Protein loads of 75 and 100 g resulted in lower glycaemic excursions than control in the 60-120 min postprandial interval, but higher excursions in the 180-300 min interval. In comparison with 20 g glucose, the large protein loads resulted in significantly delayed and sustained glucose excursions, commencing at 180 min and continuing to 5 h. CONCLUSIONS: Seventy-five grams or more of protein alone significantly increases postprandial glycaemia from 3 to 5 h in people with Type 1 diabetes mellitus using intensive insulin therapy. The glycaemic profiles resulting from high protein loads differ significantly from the excursion from glucose in terms of time to peak glucose and duration of the glycaemic excursion. This research supports recommendations for insulin dosing for large amounts of protein.

Optical design of two spectrographs for the Canada-France-Hawaii telescope.

Optical designs of two new spectrographs for the Canada-France-Hawaii telescope Cassegrain focus are described. Also given is a summary of the design procedure using the Dominion Astrophysical Observatory optical design code OPTESA (optical system optimization by educated simulated annealing). The f/2.8 multiobject spectrograph has a field of view of 10 min of-arc, whereas the f/10 subsecond of arc imaging spectrograph has a field of view of 3 armin. They are to be commissioned in 1991.

Telescope baffle performance for Lyman Far Ultraviolet Spectrographic Explorer.

The Lyman Far Ultraviolet Spectrographic Explorer telescope is a Wolter type II glancing incidence design with an aperture of 64 cm. Because the spacecraft is required to guide on stars fainter than m(v) = 16, a visible light baffle is necessary to protect the field of view from the stray light that results from out-of-field bright sources. Such a baffle system is described here. Total point-source transmittances are computed for incident beams in the range 0-70°. Estimates for background brightness on the detector are made for the contribution from direct sunlight and earthshine. Scattering from the black surfaces of the baffle, the vanes, and diffraction at the structure's edges are taken into consideration.

Fine-error-sensor camera designs and performance for the Lyman Far Ultraviolet Spectrographic Explorer telescope.

The Lyman Far Ultraviolet Spectrographic Explorer telescope is a glancing-incidence type with a highly curved focal surface. Because the instrument is required to guide on stars in the visible range fainter than m(v) = 16 over at least a 10-arcmin field, it is necessary to reimage the field to one, which is sufficiently flat and of appropriate scale for registration by a CCD. We present two camera designs that satisfy this requirement and discuss their overall performance.