Dietary acid load and risk of cardiovascular disease: a prospective population-based study

Increased dietary acid load May elevate the risk of coronary artery disease severity: Findings from a cross-sectional study

Background

Chronic low-grade metabolic acidosis appears to play a role in the development of chronic disorders. This study aims to examine the relationship between Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP) and the risk of severe coronary artery disease (CAD) in participants undergoing elective angiography.

Methods

In this cross-sectional study, the data of 895 participants from the Nutrition Heshmat Registry (NUTHER) was collected. Dietary data were obtained using a validated food frequency questionnaire to calculate PRAL and NEAP. Participants were categorized into severe CAD (Gensini score≥60; n = 526) and non-severe CAD (Gensini score<60; n = 369). Logistic regression was conducted to evaluate the odds ratio (OR) and 95 % confidence interval (95 %CI). Restricted cubic spline (RCS) regression was employed to explore potential nonlinear associations between PRAL, and NEAP and severe-CAD risk.

Results

After adjusting for potential confounding factors, participants in the third to fourth quartiles of energy-adjusted PRAL and NEAP exhibited higher odds of severe CAD that were approximately 1.62-1.80 times and 1.67-2.76 times greater, respectively, compared to those in the 1stquartiles (4thquartile ORs(95 %CI) for: PRAL: 1.62 (1.05, 2.51); and NEAP: 1.67 (1.07, 2.61) (P-for-trend<0.021). RCS analysis showed a linear dose-response relationship between elevated PRAL and severe CAD risk (P-for-overall-trend = 0.0176; P-for-nonlinearity = 0.1552), and a nonlinear association between higher NEAP and increased severe CAD risk (P-for-overall-trend = 0.0001; P-for-nonlinearity = 0.006).

Conclusion

The findings indicate a significant association between higher dietary acid load and increased risk of severe CAD, suggesting that a more acidic diet may contribute to the progression of atherosclerosis. However, further prospective studies are necessary to validate these observations.

The association between dietary acid load and risk of gallstone: a case-control study

BACKGROUND AND AIM

While dietary factors are known to influence gallstone disease (GD), the specific role of dietary acid load (DAL) remains unclear. This study aimed to explore the relationship between DAL and GD risk using a case-control design.

METHODS

The study included 189 adults with newly diagnosed GD and 342 controls. Anthropometric data were collected, and DAL was calculated using the potential renal acid load (PRAL) and net endogenous acid production (NEAP) indices. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI), adjusting for confounders.

RESULTS

Participants in the higher tertiles of both PRAL and NEAP scores showed notably elevated grain consumption and reduced intake of vegetables and fruits (P < 0.001). Conversely, an inverse relationship was observed between NEAP scores and intake of legumes, nuts, and seeds (P = 0.044). After adjustment for confounders, the risk of GD was 25% higher in the second tertile (OR: 1.25; 95% CI: 0.9, 2.3) and 51% higher in the third tertile (OR: 1.51; 95% CI: 0.54, 1.36) of PRAL compared to the first tertile (P trend = 0.023). A similar trend was seen for NEAP, with a 19% increased risk in the second tertile (OR: 1.19; 95% CI: 0.78, 1.84) and 48% in the third tertile (OR: 1.48; 95% CI: 0.9, 2.3) relative to the first tertile.

CONCLUSIONS

Higher dietary acid load is associated with an increased risk of GD. Further studies are needed to confirm these findings and elucidate underlying mechanisms.

Dietary acid load and the odds of knee osteoarthritis: a case-control study

Knee osteoarthritis (KOA) is a common form of arthritis that leads to joint pain and reduced mobility, especially among older adults. Recent studies indicate that dietary acid load (DAL) may play a role in the development of KOA by promoting systemic inflammation. This case-control study aims to investigate the relationship between DAL and KOA in adults aged 40 and older. A total of 150 newly diagnosed cases of KOA and 300 age-, sex-, and BMI-matched controls were recruited from Zabol County, Iran. Dietary intake was assessed using a validated food frequency questionnaire, and DAL was calculated based on nutrient content. Logistic regression was used to estimate the odds of KOA across DAL quartiles, adjusting for confounding factors such as physical activity, smoking, and supplement use. Individuals in the highest quartile of DAL had significantly higher odds of developing KOA compared to those in the lowest quartile (OR: 2.48, 95% CI: 1.36-4.51, p = 0.003), after adjusting for potential confounders. Additionally, the odds of developing KOA was found to increase with increasing quartiles of DAL in both male (OR: 2.52, 95%CI: 1.13 to 5.65, p = 0.024) and female (OR: 2.55, 95%CI: 1.06 to 6.31, p = 0.031) participants, after adjusting for potential confounding variables. This study demonstrates a significant association between high DAL and increased odds of KOA. Reducing DAL through dietary interventions may be a promising strategy for managing KOA, especially in aging populations. Further longitudinal studies are required to confirm these findings and explore causal relationships.

Dietary Acid Load and Human Health: A Systematic Review and Meta-analysis of Observational Studies

CONTEXT

Dietary acid load (DAL) plays an important role in different aspects of human health.

OBJECTIVE

The aim of this meta-analysis was to systematically synthesize the observational evidence reporting on the associations between the DAL (represented by a potential renal acid load [PRAL] and net endogenous acid production [NEAP]) and a range of health outcomes.

DATA SOURCES

A systematic search of Medline (via PubMed), EMBASE, Scopus, and Web of Science was performed to identify eligible studies.

DATA EXTRACTION

Study screening and risk-of-bias assessment were conducted by 2 independent reviewers.

DATA ANALYSIS

The credibility of each outcome was graded based on predefined criteria: pooled effect size with corresponding 95% CI, 95% prediction interval, heterogeneity, small-study effect, and excess significance bias. In total, 118 observational studies (case-control [n = 22], cross-sectional [n = 65], and cohort [n = 31]) on 38 outcomes were included, incorporating a total population of 1 014 081 participants. Overall, 21/37 and 20/38 of the outcomes reported statistically significant effect sizes for PRAL and NEAP, respectively. The credibility of the evidence for PRAL was rated convincing (class I) for type 2 diabetes (T2D), and as highly suggestive evidence (class II) for overall cancer and systolic blood pressure. By assessing the credibility of the evidence for NEAP, T2D and overall cancer presented convincing evidence (class I) and breast cancer presented highly suggestive evidence (class II). The remaining outcomes presented class III (suggestive) or lower evidence (weak or no association).

CONCLUSION

The higher acid-forming potential of diet was associated with a higher risk of T2D and overall cancer. Since this meta-analysis included observational studies and some of the associations were graded as weak, caution should be exercised in interpreting these associations. Further cohort studies are required with consideration of other factors that can cause biases.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022336050.

Evaluation of the relationship between dietary acid load and cardiovascular risk factors in patients with type 2 diabetes: a case-control study

Backround

Diets high in dietary acid load are thought to be associated with metabolic diseases. However, the number of studies examining the relationship between dietary acid load and metabolic diseases in Turkey is insufficient. The aim of this study was to investigate the relationship between cardiovascular disease risk factors and dietary acid load in individuals with type 2 diabetes.

Materials and methods

In this case-control study, 51 participants aged 30-65 years with type 2 diabetes and 59 participants in the control group were included. Blood pressure and biochemical findings were measured. Anthropometric measurements and body composition measurements were made. Dietary intake was assessed using a 3-day (1 day on weekends, 2 days on weekdays) food consumption record. Dietary acid load scores, including potential renal acid load (PRAL) and net endogenous acid production (NEAP), were calculated based on dietary intake. NEAP and PRAL scores were categorized as low and high according to the median value. Smoking status, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), trigylceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL), waist-hip ratio (WHR), waist-to- height ratio (WtHR), hemoglobin and fat mass (%) were evaluated as cardiovascular risk factors.

Results

The cut-off values of PRAL and NEAP were 3.61 and 44.78 mEq/d, respectively. After adjustment for various covariates, a significant positive association between PRAL and TG levels was observed in the diabetic group [odds ratio (OR), 5.98; 95% CI, 1.45-24.67; p = 0.013]. In contrast, a negative association was found between PRAL and SBP in the control group [odds ratio (OR), 0.21; 95% CI, 0.05-0.83; p = 0.026]. However, these associations were not observed for NEAP values in either group.

Conslusions

A higher PRAL value was consistently associated with higher TG level, but other cardiovascular risk factors were not. More longitudinal and interventional studies are needed to better establish a causal effect between dietary acid load and cardiovascular risk factors in individuals with diabetes.

Association between albumin-corrected anion gap level and the risk of acute kidney injury in intensive care unit

PURPOSE

This study was to investigate the association between albumin-corrected anion gap (AG) (ACAG) levels and the risk of acute kidney injury (AKI) in intensive care unit (ICU) patients.

METHODS

The ICU patients of this retrospective cohort study were collected from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database between 2008 and 2019. ACAG = AG + {4.4 - [albumin (g/dl)]} × 2.5. The incidence of AKI was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) definition. The logistic regression model was used to evaluate the association between ACAG levels and the risk of AKI. Subgroup analyses were applied based on age, gender, mechanical ventilation, vasopressors, the Charlson comorbidity index (CCI), and the Simplified Acute Physiology Score II (SAPS II).

RESULTS

Totally, 5586 patients were enrolled, of which 1929 patients (34.53%) occurred AKI. The higher levels of ACAG were associated with the risk of AKI in ICU patients, with the odds ratio (OR) value being 1.23 [95% confidence interval (CI): 1.22-1.24, P = 0.005] in ACAG level between 16.5 and 19.5, and OR value being 1.20 (95% CI 1.16-1.24, P = 0.016) in ACAG level > 19.5. A higher ACAG level was associated with a higher risk of AKI in ICU patients aged < 65 years, in ICU patients of female gender, in ICU patients who used mechanical ventilation, in ICU patients who did not use vasopressors, in patients without cardiogenic shock, and in ICU patients with CCI ≥ 2, and SAPS II > 31 (all P < 0.05).

CONCLUSION

There is an association between ACAG level and the risk of AKI in ICU patients. A higher ACAG value in ICU patients should therefore receive more attention.

A high dietary acid load can potentially exacerbate cardiometabolic risk factors: An updated systematic review and meta-analysis of observational studies

AIMS

Chronic metabolic acidosis has been shown to be associated with cardiometabolic risk factors. The aim of the currently updated meta-analysis was to explore the association between Potential Renal Acid Load (PRAL) and Net Endogenous Acid Production (NEAP) with these risk factors.

DATA SYNTHESIS

Databases were searched up to May 2023. The mean of waist circumference (WC), body mass index (BMI), high- and low-density lipoprotein-cholesterol (HDL-C and LDL-C), triglyceride (TG), total cholesterol (TC), fasting blood sugar (FBS), and systolic- and diastolic blood pressure (SBP and DBP) in highest category vs lowest categories of NEAP and PRAL were recorded. Effect sizes were generated as weighted mean difference (WMD). Results showed that SBP, DBP, and WC had a significant difference in the upper and lower categories of PRAL (WMDSBP: 1.466 mmHg; 95% CI: 2.121, -0.811; P<0.001, WMDDBP: 0.710 mmHg; 95 % CI: 1.170, -0.249; P=0.003, and WMDWC: 0.819 cm; 95% CI: 1.446, -0.192; P=0.010) or NEAP (WMDSBP: 1.690 mmHg; 95% CI: 2.789, -0.591; P=0.003, WMDDBP: 1.076 mmHg, and WMDWC: 1.325 cm; 95% CI: 1.901, -0.749; P<0.001; 95% CI: 1.938, -0.214; P =0.014). The lowest versus highest categories of dietary PRAL were associated with lower BMI (WMDPRAL: 0.297 kg/m2; 95 % CI: 0.440, -0.154; P<0.001) and TG (WMD: 2.280 mg/dl; 95%CI: 3.828, -0.732; P=0.004; I2=99.4 %; P<0.001).

CONCLUSIONS

High DAL can be considered as an independent risk factor for increasing anthropometric indices, blood pressure, and TG. This study registered in the PROSPERO database (Registration No. CRD42023402985).

Low bone mineralization in phenylketonuria may be due to undiagnosed metabolic acidosis

Background

Dietary intervention is to date the mainstay treatment to prevent toxic phenylalanine (Phe) accumulation in PKU patients. Despite success preventing central nervous system damage, there is increasing evidence of possible other unfavorable outcomes affecting other systems, e.g. kidney and bone; underlying mechanisms are yet to be fully elucidated.

Methods

This observational, cross-sectional and descriptive study investigated 20 adult with PKU evaluating biochemical parameters, BMD measurements and extrapolating data from 3-days food records and protein substitutes (PS) and special low protein foods (SLPF) composition.

Results

Blood gas venous analysis (VBG) indices were indicative of metabolic acidosis in 60% of PKU patients and VBG pH significantly correlated with BMD's Z-score (p-value = 0.022) even if its overall mean was in range (-1.29). Low bone mineral density for chronological age (Z-score < - 2.0) was found in 4 patients (20%). Indices of kidney function were not impaired. All used PS had a moderate excess of acidity, while SLPF were alkalizing and type/variety of consumed vegetables did not determine significant changes in acid-base equilibrium. Total intakes of potassium and magnesium were lower than expected.

Discussion

PKU patients seem to be at risk of metabolic acidosis, directly linked to possible low bone mineralization. This may be related to the acidic composition of PS, potentially capable of acidifying the entire diet. Reported low intakes of potassium and magnesium may be relevant to these observations. Further studies are needed to better address these topics.

Higher dietary acid load is associated with hyperuricemia in Chinese adults: a case-control study

BACKGROUND

This study aims to explore the association between dietary acid load and hyperuricemia in Chinese adults.

METHODS

A case-control study was conducted. Adult participants with hyperuricemia were recruited as the cases and those without hyperuricemia were as the controls. Food consumption was evaluated by food frequency questionnaire (FFQ). Dietary acid load was assessed by potential renal acid load (PRAL) and net endogenous acid production (NEAP). Dietary acid load was divided into four levels: the first quartile (Q1), the second quartile (Q2), the third quartile (Q3) and the fourth quartile (Q4). Logistic regression model was applied for exploring the association between dietary acid load (PRAL and NEAP) and hyperuricemia. Odds ratio (OR) and its correspondence confidence interval (CI) were computed.

RESULTS

A total of 290 participants were eligible in this study, in which there were 143 individuals in case group and 147 in control group. A higher level of PRAL was found to be associated with odds of hyperuricemia. ORs of hyperuricemia for Q2, Q3 and Q4 of PRAL were 2.74 (95%CI: 1.94 ~ 3.88, p-value: 0.004), 2.90 (95%CI: 2.05 ~ 4.10, p-value: 0.002) and 3.14 (95%CI: 2.22 ~ 4.45, p-value: 0.001), respectively. There was a positive association between elevated NEAP and hyperuricemia. OR of hyperuricemia for Q2 was not material significance (OR:1.54, 95%CI: 0.93 ~ 2.53, p-value: 0.210), however, ORs of hyperuricemia for Q3 (OR: 2.40, 95%CI: 1.70 ~ 3.38, p-value: 0.011) and Q4 (OR: 3.27, 95%CI: 2.31 ~ 4.62, p-value: 0.001) were statistically significant.

CONCLUSION

Higher level of dietary acid load was found to be associated with hyperuricemia in Chinese adults, indicative of advocation of a well-balanced diet in this population.