Precision xtra system

Glucose monitoring of tail vein blood from NSG mice was performed with a Precision Xtra system (Abbott Diabetes Care Inc.). Blood was assayed from day −1 to day 149 post injections.

In week 4, we provide participants with a home-based blood ketone-monitoring device (Precision Xtra System; Abbott Diabetes Care, Alameda, California) and ketone strips, which participants use with the device to measure β-hydroxybutyrate (BOHB) in the blood. This method was recently used in a CR diet intervention for individuals with T2DM [39 (link)]. We teach participants how to use the meter in person and ask them to measure their blood ketones before dinner, 2 to 3 times a week, on alternating days. Participants are asked to report ketone results via online survey on a weekly basis. The meters store data, which staff check at every weekly class (starting in week 5) and every monthly class (starting in week 16) to confirm self-reported measurements. Values collected by meters will be used for analysis; however, if their equipment malfunctions (eg, breakage or loss), we will use available self-reported values. For this trial, we define nutritional ketosis as a BOHB level between 0.3 and 3.0 mmol/L. Although the level of carbohydrate restriction needed to achieve ≥0.3 BOHB varies between individuals, in our experience, most individuals need to restrict carbohydrate intake to below 50 g per day of nonfiber carbohydrate to achieve nutritional ketosis.

In week 4, we provided participants with a home-based blood ketone monitoring device (Precision Xtra® System; Abbott Diabetes Care, Alameda, California) and ketone strips. Participants used these supplies to measure β-hydroxybutyrate (BOHB) [35 (link)] in their blood. We taught participants how to use the monitoring device in person and asked them to measure their blood ketones before dinner, two to three times a week, on alternating days. Participants reported ketone measurements via an online survey on a weekly basis. The ketone monitoring devices store data, which staff checked at every weekly class (starting in week 5) and every monthly class (starting at month 4) to confirm self-reported measurements. We defined our target BOHB level as between 0.3 and 3.0 mmol/L. Although the level of carbohydrate restriction needed to achieve ≥0.3 BOHB varies between individuals, most individuals need to restrict to fewer than 50 g per day of non-fiber carbohydrate to achieve this blood ketone range [36 (link)]. For the current analyses, we used ketone data from the final five weeks of the 6-month study period.