Background

A high glycemic index (GI) and glycemic load (GL) diet may stimulate acne proliferative pathways by influencing biochemical factors associated with acne. However, few randomized controlled trials have examined this relationship, and this process is not completely understood.

Objective

This study examined changes in biochemical factors associated with acne among adults with moderate to severe acne after following a low GI and GL diet or usual eating plan for 2 weeks.

Design

This study utilized a parallel randomized controlled design to compare the effect of a low GI and GL diet to usual diet on biochemical factors associated with acne (glucose, insulin, insulin-like growth factor [IGF]-1, and insulin-like growth factor binding protein [IGFBP]-3) and insulin resistance after 2 weeks.

Participants

Sixty-six participants were randomly allocated to the low GI and GL diet (n=34) or usual eating plan (n=32) and included in the analyses.

Main outcome measures

The primary outcomes were biochemical factors of acne and insulin resistance with dietary intake as a secondary outcome.

Statistical analyses

Independent sample t tests assessed changes in biochemical factors associated with acne, dietary intake, and body composition pre- and postintervention, comparing the two dietary interventions.

Results

IGF-1 concentrations decreased significantly among participants randomized to a low GI and GL diet between pre- and postintervention time points (preintervention=267.3±85.6 mg/mL, postintervention=244.5±78.7 ng/mL) (P=0.049). There were no differences in changes in glucose, insulin, or IGFBP-3 concentrations or insulin resistance between treatment groups after 2 weeks. Carbohydrate (P=0.019), available carbohydrate (P<0.001), percent energy from carbohydrate (P<0.001), GI (P<0.001), and GL (P<0.001) decreased significantly among participants following a low GI/GL diet between the pre- and postintervention time points. There were no differences in changes in body composition comparing groups.

Conclusions

In this study, a low GI and GL diet decreased IGF-1 concentrations, a well-established factor in acne pathogenesis. Further research of a longer duration should examine whether a low GI and GL diet would result in a clinically meaningful difference in IGF-1 concentrations leading to a reduction in acne. This trial was registered at clinicaltrials.gov as NCT02913001.

中文翻译：

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低血糖指数和血糖负荷饮食会降低患有中度和严重痤疮的成年人的胰岛素样生长因子-1：短期，2周随机对照试验

背景

高血糖指数（GI）和高血糖负荷（GL）饮食可能会通过影响与痤疮相关的生化因素来刺激痤疮的增殖途径。但是，很少有随机对照试验检查过这种关系，并且这个过程还不完全清楚。

客观的

这项研究检查了在低GI和GL饮食或常规饮食计划2周后，中度至重度痤疮成人中与痤疮相关的生化因子变化。

设计

这项研究采用平行随机对照设计，比较低GI和GL饮食与普通饮食对痤疮相关的生化因子（葡萄糖，胰岛素，胰岛素样生长因子[IGF] -1和胰岛素样生长因子）的影响结合蛋白[IGFBP] -3）和2周后的胰岛素抵抗。

参加者

66名参与者被随机分配到低GI和GL饮食（n = 34）或常规饮食计划（n = 32）并纳入分析。

主要观察指标

主要结果是痤疮和胰岛素抵抗的生化因素，而饮食摄入是次要结果。

统计分析

独立样本t检验比较了两种饮食干预措施，评估了痤疮，饮食摄入和干预前后身体成分相关的生化因子变化。

结果

在干预前和干预后的时间点之间（干预前= 267.3±85.6 mg / mL，干预后= 244.5±78.7 ng / mL），随机分配至低GI和GL饮食的参与者中IGF-1浓度显着降低（P = 0.049）。2周后治疗组之间的葡萄糖，胰岛素或IGFBP-3浓度或胰岛素抵抗的变化无差异。碳水化合物（P = 0.019），可用碳水化合物（P <0.001），碳水化合物的能量百分比（P <0.001），GI（P <0.001）和GL（P在干预前和干预后的时间点之间，在低GI / GL饮食的情况下，参与者中的<0.001）显着降低。比较组的身体成分变化无差异。

结论

在这项研究中，低GI和GL饮食降低了IGF-1的浓度，IGF-1的浓度是痤疮发病机理中公认的因素。较长时间的进一步研究应检查低GI和GL饮食是否会导致IGF-1浓度在临床上有意义的差异，从而导致痤疮减少。这项试验是在注册clinicaltrials.gov为NCT02913001。