Laboratory of Investigation of Chronic Diseases, Department of Physiological Sciences, Federal University of Santa Catarina, Florianópolis, 88040-900, SC, Brazil; Graduate Program in Nutrition, Health Sciences Centre, Federal University of Santa Catarina, Florianópolis, 88040-900, SC, Brazil.
Graduate Program in Nutrition, Health Sciences Centre, Federal University of Santa Catarina, Florianópolis, 88040-900, SC, Brazil.
Clin Nutr ESPEN. 2022 Jun;49:341-347. doi: 10.1016/j.clnesp.2022.03.025. Epub 2022 Apr 4.
BACKGROUND & AIMS: Diabetes mellitus (DM) and cardiovascular disease (CVD) are among the biggest causes of death and health expenses worldwide. A higher dietary acid load (DAL) is associated with chronic low-grade metabolic acidosis, and may increase the risk of insulin resistance (IR), DM, hypertension, and CVD mortality. However, the association between DAL and IR still lacks population-based studies to confirm laboratory findings.
This is a population-based observational study including a sample of 545 individuals aged 25-64 years from Florianópolis (Southern Brazil) who participated in the EpiFloripa cohort study. All diet variables were obtained through two 24-h Food Recalls adjusted to obtain an estimate of habitual food consumption. DAL was measured by Potential Renal Acid Load (PRAL) and Net Endogenous Acid production (NEAP). Fasting blood samples were obtained from all participants. The primary outcome was IR, which was estimated by HOMA-IR. Secondary outcomes included HOMA-β, glycosylated hemoglobin, and fasting blood glucose and insulin. Multiple linear regression models adjusted for sociodemographics, lifestyle, and clinical variables were used for analysis, with exposure and outcome variables standardized as Z-scores to allow comparability of the results.
The mean PRAL and NEAP in the sample were 16.9 ± 4.8 and 66.1 ± 7.1 mEq/day, respectively. The average HOMA-IR score was 2.4 ± 1.6. In adjusted analyses, PRAL was positively associated with HOMA-IR, fasting insulin, and fasting blood glucose (p-value <0.05 in all cases), but not with HOMA-β or glycated hemoglobin. NEAP also showed a direct-trend relationship with HOMA-IR and fasting insulin, but not with fasting blood glucose or the other outcomes. The strongest association was between PRAL and HOMA-IR (β, 0.20; 95% CI, 0.06-0.35).
A higher DAL was consistently associated with higher IR and insulin levels but not with other glycaemic parameters. Apparently, β-pancreatic cells function is not affected by DAL in this population. This is the first study that describes the DAL in a population-based sample of adults in Latin America and in a middle-income country population. Further longitudinal and interventional studies are required to establish a better causal effect between DAL and IR.
糖尿病（DM）和心血管疾病（CVD）是全球范围内导致死亡和健康支出的最大原因之一。较高的膳食酸负荷（DAL）与慢性低度代谢性酸中毒有关，可能增加胰岛素抵抗（IR）、DM、高血压和 CVD 死亡率的风险。然而，DAL 和 IR 之间的关联仍缺乏人群研究来证实实验室发现。
这是一项基于人群的观察性研究，包括来自巴西弗洛里亚诺波利斯（南部）的 545 名年龄在 25-64 岁的参与者，他们参加了 EpiFloripa 队列研究。所有饮食变量均通过两次 24 小时食物回忆获得，以获得习惯性食物消费的估计值。DAL 通过潜在肾酸负荷（PRAL）和净内源性酸生成（NEAP）来测量。所有参与者均采集空腹血样。主要结局为 IR，通过 HOMA-IR 估计。次要结局包括 HOMA-β、糖化血红蛋白和空腹血糖及胰岛素。采用多元线性回归模型调整社会人口统计学、生活方式和临床变量进行分析，将暴露和结局变量标准化为 Z 分数，以允许比较结果。
样本中的平均 PRAL 和 NEAP 分别为 16.9 ± 4.8 和 66.1 ± 7.1 mEq/天。平均 HOMA-IR 评分为 2.4 ± 1.6。在调整分析中，PRAL 与 HOMA-IR、空腹胰岛素和空腹血糖呈正相关（所有情况下 p 值均<0.05），但与 HOMA-β或糖化血红蛋白无关。NEAP 与 HOMA-IR 和空腹胰岛素也呈直接趋势关系，但与空腹血糖或其他结局无关。最强的关联是 PRAL 与 HOMA-IR（β，0.20；95%CI，0.06-0.35）之间的关联。
较高的 DAL 与更高的 IR 和胰岛素水平一致相关，但与其他血糖参数无关。显然，在该人群中，β-胰岛细胞功能不受 DAL 的影响。这是第一项描述拉丁美洲人群中基于人群的成年人 DAL 和中低收入国家人群中 DAL 的研究。需要进一步的纵向和干预研究来确定 DAL 和 IR 之间更好的因果关系。
