Dickson Jennifer L, Hewett James N, Gunn Cameron A, Lynn Adrienne, Shaw Geoffrey M, Chase J Geoffrey
Department of Mechanical Engineering, University of Canterbury, Christchurch, New Zealand.
J Diabetes Sci Technol. 2013 Jul 1;7(4):913-27. doi: 10.1177/193229681300700414.
Both stress and prematurity can induce hyperglycemia in the neonatal intensive care unit, which, in turn, is associated with worsened outcomes. Endogenous glucose production (EGP) is the formation of glucose by the body from substrates and contributes to blood glucose (BG) levels. Due to the inherent fragility of the extremely low birth weight (ELBW) neonates, true fasting EGP cannot be explicitly determined, introducing uncertainty into glycemic models that rely on quantifying glucose sources. Stochastic targeting, or STAR, is one such glycemic control framework.
A literature review was carried out to gather metabolic and EGP values on preterm infants with a gestational age (GA) <32 weeks and a birth weight (BW) <2 kg. The data were analyzed for EGP trends with BW, GA, BG, plasma insulin, and glucose infusion (GI) rates. Trends were modeled and compared with a literature-derived range of population constant EGP models using clinically validated virtual trials on retrospective clinical data.
No clear relationship was found for EGP and BW, GA, or plasma insulin. Some evidence of suppression of EGP with increasing GI or BG was seen. Virtual trial results showed that population-constant EGP models fit clinical data best and gave tighter control performance to a target band in virtual trials.
Variation in EGP cannot easily be quantified, and EGP is sufficiently modeled as a population constant in the neonatal intensive care insulin-nutrition-glucose model. Analysis of the clinical data and fitting error suggests that ELBW hyperglycemic preterm neonates have unsuppressed EGP in the higher range than that seen in literature.
应激和早产均可在新生儿重症监护病房诱发高血糖，而高血糖又与不良预后相关。内源性葡萄糖生成（EGP）是机体利用底物生成葡萄糖的过程，对血糖（BG）水平有贡献。由于极低出生体重（ELBW）新生儿本身脆弱，无法明确测定真正的空腹EGP，这给依赖葡萄糖来源量化的血糖模型带来了不确定性。随机靶向法（STAR）就是这样一种血糖控制框架。
进行文献综述，收集胎龄（GA）<32周、出生体重（BW）<2 kg的早产儿的代谢和EGP值。分析这些数据中EGP随BW、GA、BG、血浆胰岛素和葡萄糖输注（GI）速率的变化趋势。利用回顾性临床数据进行临床验证的虚拟试验，对这些趋势进行建模，并与文献得出的一系列群体恒定EGP模型进行比较。
未发现EGP与BW、GA或血浆胰岛素之间存在明确关系。有证据表明，随着GI或BG升高，EGP受到抑制。虚拟试验结果表明，群体恒定EGP模型最适合临床数据，并且在虚拟试验中能更严格地控制目标范围。
EGP的变化不易量化，在新生儿重症监护胰岛素-营养-葡萄糖模型中，将EGP充分建模为群体常数即可。对临床数据和拟合误差的分析表明，ELBW高血糖早产儿的EGP未受抑制，且处于比文献报道更高的范围。
