Caution Urged in Patients With Impaired Kidney Function
ORANGE, CA — Diabetes affects more than 34 million—or nearly 10% of—Americans and is the seventh-leading cause of death in the U.S. The prevalence is even higher among U.S. veterans; approximately 25% of individuals who’ve served in the military have diabetes.1
Addressing diabetes is a major public health priority, as the disease can lead to serious complications that reduce quality of life and increase the risk of disability and death. Diabetes also has a major economic impact. Nationwide, 1 in 4 healthcare dollars is spent on care for people with diagnosed diabetes, and more than half of those costs are directly attributable to the disease. In particular, the VHA spends more than $200 million in outpatient care and more than $1 billion in inpatient care for veterans with diabetes.2
A recent study examines whether veterans with diabetes can benefit from a virtual coaching program modeled around a ketogenic (aka “keto”) diet, an extremely low-carb eating plan that’s meant to trigger ketosis, a metabolic state in which the body burns fat as its primary source of fuel. The diet has historically been used as a treatment for epilepsy, but it has been studied more recently as a way to improve blood glucose and manage diabetes.
“While some virtual diet interventions with coaching components have been shown to be effective in achieving short-term weight loss and improving glucose control, less is known about the impact of coaching programmes with a specific ketogenic (keto) diet component,” the study authors wrote.
In the study, published in the journal Diabetes, Obesity and Metabolism, the researchers analyzed the VA electronic health records of 590 veterans with diabetes
who were also overweight or obese to evaluate the impact of a five-month ketogenic diet and virtual coaching intervention from Virta Health, a private sector digital healthcare company. In April 2019, the VA initiated a pilot program in which veterans were given access to a Virta intervention that offers health data monitoring and personalized coaching to encourage adherence to a ketogenic diet. In order to participate in the pilot program, patients were required to have a current diabetes diagnosis and be taking at least one diabetes medication.
The research team studied how the intervention affected diabetes outcomes as well as diabetes-related healthcare costs, including outpatient and inpatient care utilization and prescription drug utilization and costs. They used a “difference in differences” method to compare two groups of diabetes patients—the veterans enrolled in the Virta program and those on the waitlist for the program—before and after the intervention.
Significant Improvement
They found that the Virta program was associated with a significant improvement in markers of glucose control and metabolic health, including hemoglobin A1c and body mass index. The program also saved patients money and curbed their healthcare utilization. Veterans enrolled in the program reduced their number of monthly insulin prescriptions and monthly diabetes-related medications, while spending an average of $34.54 less on diabetes-related medications per month.
“[The cost savings] is especially important given the high financial burden of chronic disease care to the VA and other large healthcare delivery systems,” said the study’s lead author Kiersten Strombotne, PhD, assistant professor of health law, policy and management at the Boston University School of Public Health and an investigator at the Partnered Evidence-Based Policy Resource center (PEPReC) at the VA Boston Healthcare Service.
While the research shows that veterans with diabetes could experience short-term benefits from virtual diet and coaching interventions designed to improve markers of diabetes care, Strombotne notes that the study design makes it difficult to ascertain the specific factors that contribute to a successful program.
“It’s unclear whether this intervention worked well as a result of the diet, the coaching component, the medication management or some combination of the three,” she said. “Being able to tease out the most important components will help us refine innovative approaches to diabetes prevention and treatment in the future.”
Another study, led by the University of California Irvine in Orange, CA, and including participation from the Memphis, TN, VAMC, cautioned about use of high protein diets in patients with impaired kidney function.
The report in the American Journal of Clinical Nutrition pointed out, “High-protein diets (e.g., Paleo, Atkins, South Beach, ketogenic) have gained popularity as a means to promote weight loss and avoid excess carbohydrate consumption. Yet in chronic kidney disease (CKD) patients, evidence suggests low dietary protein intake (DPI) leads to attenuation of kidney function decline, although concerns remain for risk of protein-energy wasting.”4
The study team sought to determine associations of DPI with mortality in a nationally representative cohort of U.S. adults, stratified by kidney function. To do that, researchers analyzed the association between daily DPI scaled to actual body weight (ABW), ascertained by 24-hour dietary recall on one hand with all-cause mortality on the other. The study involved 27,604 continuous National Health and Nutrition Examination Survey (NHANES) adult participants from 1999-2010; those respondents were stratified according to impaired vs. normal kidney function (estimated glomerular filtration rates <60 compared with ≥60 ml/min/1.72 m2, respectively).
Also examined was the relationship between high biological value (HBV) protein consumption with mortality.
Results indicated that participants with impaired kidney function, defined as a high DPI of ≥1.4 g/kg ABW/day, had higher mortality, while lower DPI levels were not associated with mortality (reference, 0.6 to <1.0 g/kg ABW/day). Adjusted hazard ratios (aHRs) were 1.09 (95% CI: 0.90, 1.32), 1.03 (95% CI: 0.82, 1.29) and 1.37 (95% CI: 1.02, 1.85) for DPI <0.6, 1.0 to <1.4 and ≥1.4 g/kg ABW/day, respectively.
“Yet in participants with normal kidney function, a low DPI of <0.6 g/kg ABW/day was associated with higher mortality, whereas higher DPI levels were not associated with death: the aHRs were 1.18 (95% CI: 1.04, 1.34), 0.92 (95% CI: 0.81, 1.04), and 0.99 (95% CI: 0.85, 1.16) for DPI <0.6, 1.0 to <1.4, and ≥1.4 g/kg ABW/day, respectively,” according to the researchers. “The highest 2 tertiles of HBV consumption were associated with higher mortality in participants with impaired kidney function.”
The authors called for further studies to elucidate the specific pathways between higher DPI and mortality in CKD.
- American Diabetes Association. “Statistics About Diabetes.” https://www.diabetes.org/resources/statistics/statistics-about-diabetes
- Peterson, Matthew. Economic Costs of Diabetes in the U.S. in 2017. Diabetes Care. Published May 2018. DOI: 10.2337/dci18-0007
- Strombotne, Kiersten L., Lum, Jessica, Ndugga, Nambi J., Utech, Anne E., et al. Effectiveness of a ketogenic diet and virtual coaching intervention for patients with diabetes: A difference-in differences analysis. Diabetes, Obesity and Metabolism. Published August 5, 2021. DOI: 10.1111/dom.14515
- Narasaki Y, Okuda Y, Moore LW, You AS, Tantisattamo E, Inrig JK, Miyagi T, Nakata T, Kovesdy CP, Nguyen DV, Kalantar-Zadeh K, Rhee CM. Dietary protein intake, kidney function, and survival in a nationally representative cohort. Am J Clin Nutr. 2021 Jul 1;114(1):303-313. doi: 10.1093/ajcn/nqab011. PMID: 33742197; PMCID: PMC8246621.
