Tuesday, November 30, 2021

Dietary and nutrition guidance for the holidays and beyond

 - Kenny Lin, MD, MPH

Still feeling the aftereffects of Thanksgiving dinner? You're hardly alone. As the days get shorter and people look forward to holiday celebrations, three recent dietary and nutrition guidelines provide practical advice for physicians and patients.

The 2020-2025 Dietary Guidelines for Americans, summarized in Practice Guidelines in the November issue of AFP, are the latest iteration of a scientific collaboration between the U.S. Departments of Agriculture (USDA) and Health and Human Services dating back to 1980. The current report provides guidance for healthy eating across a person's lifespan, emphasizing dietary patterns with nutrient-dense foods and beverages:

At least one-half of food eaten should be fruits and vegetables, especially whole fruits and vegetables of a variety of colors. The core elements of the other half of food that should be eaten include grains, dairy, protein, and oils with lower saturated fat. At least one-half of grain servings should be whole grains. Minimize alcohol use and consumption of foods with added sugar, saturated fat, and sodium.

In an accompanying editorial, Drs. Amy Locke and Rachel Goossen observed that "although many of the recommendations are widely accepted, ... criticisms revolve around the authors' reported financial ties to the food industry and the discrepancies between the published guidelines and the recommendations submitted to the authors by the scientific advisory committee." Examples of such discrepancies include the Dietary Guidelines' overemphasis on consuming dairy and animal-based proteins and insufficient limits on alcohol use. Drs. Locke and Goossen suggested that "the most accessible way to use the information included in the report is through the USDA's MyPlate website and app" that organize advice by food groups and subgroups.

Recognizing that nearly 9 in 10 adults consume more sodium than the National Academy of Medicine's Chronic Disease Risk Reduction (CDRR) intake of 2,300 mg/day, the U.S. Food and Drug Administration recently finalized voluntary guidance for industry that aims to reduce the average American's daily sodium intake by 12% (from 3,400 to 3,000 mg/day) over the next two and a half years. Industry cooperation is critical because more than 70% of sodium intake comes from packaged food and food prepared away from home. Whether these goals will be achieved in the absence of an enforcement mechanism is unclear, as the sodium content of popular commercially processed and restaurant foods has changed little over the past decade.

Finally, the U.S. Preventive Services Task Force reiterated its 2014 recommendation that found insufficient evidence to assess the benefits and harms of screening for vitamin D deficiency in asymptomatic adults. In a Putting Prevention into Practice case study in AFP, Drs. Howard Tracer and Robert West noted that due to individual variability, "no one serum vitamin D level cutoff point defines deficiency, and no consensus exists regarding the precise serum levels of vitamin D that represent optimal health or sufficiency." In a previous editorial, I observed that frequent measurement of vitamin D levels in clinical practice is inconsistent with the evidence. As for supplementation, "family physicians should also counsel patients on the recommended dietary allowance for vitamin D (600 IU per day in adults 70 years and younger, and 800 IU per day in adults older than 70 years), and discourage most patients from using supplements, especially in dosages near or above the tolerable upper limit of 4,000 IU per day."

Monday, November 22, 2021

Do the benefits of medical cannabinoids outweigh the harms?

 - Jennifer Middleton, MD, MPH

A recent systematic review and accompanying BMJ Clinical Practice Guideline have been creating media buzz regarding medical marijuana and cannabinoids. The systematic review authors comprehensively searched a broad range of databases for randomized controlled trials of at least 20 participants with chronic pain who were followed for a minimum of 1 month. They identified 32 trials with a total of nearly 5200 participants to include in the systematic review. Study durations ranged from 1.0-5.5 months, and most (28) studied non-cancer-related chronic pain. Most studies (29) compared medical cannabis and/or cannabinoids with placebo. After analyzing the data, the authors concluded that:

Compared with placebo, non-inhaled medical cannabis probably results in a small increase in the proportion of patients experiencing at least the minimally important difference (MID) of 1 cm (on a 10 cm visual analogue scale (VAS)) in pain relief (modelled risk difference (RD) of 10% (95% confidence interval 5% to 15%), based on a weighted mean difference (WMD) of −0.50 cm (95% CI −0.75 to −0.25 cm, moderate certainty)). Medical cannabis taken orally results in a very small improvement in physical functioning (4% modelled RD (0.1% to 8%) for achieving at least the MID of 10 points on the 100-point SF-36 physical functioning scale, WMD of 1.67 points (0.03 to 3.31, high certainty)), and a small improvement in sleep quality (6% modelled RD (2% to 9%) for achieving at least the MID of 1 cm on a 10 cm VAS, WMD of −0.35 cm (−0.55 to −0.14 cm, high certainty)). 

The authors interpreted these findings as "moderate to high certainty evidence" that the use of medical cannabis and cannabinoids was associated with a "small to very small" improvement in pain, functioning, and sleep. They also reported on adverse events that occurred more frequently in the medical cannabis and cannabinoids patients, including cognitive impairment and nausea/vomiting. 

This systematic review's findings informed an accompanying Clinical Practice Guideline in the same issue of BMJ, in which the guideline authors issued "a weak recommendation to offer a trial of non-inhaled medical cannabis or cannabinoids, in addition to standard care and management (if not sufficient), for people living with chronic cancer or non-cancer pain." The guideline development panel included three of the authors of the above systematic review, patients, and "clinicians with content expertise," who acknowledge that their recommendation "reflects a high value placed on small to very small improvements in self reported pain intensity, physical functioning, and sleep quality, and willingness to accept a small to modest risk of mostly self limited and transient harms." They acknowledge that their guideline contradicts previous guidelines issued by NICE, the American Society of Clinical Oncology, and Canadian Family Physician, arguing that those guidelines were limited by an overly "selective review of the evidence" and a "failure to consider patient values and preferences."

These conflicting guidelines attest to the continued controversy regarding the use of marijuana and/or cannabinoids in medicine. Currently, 36 US states and 4 US territories permit their use. As this recent JAMA editorial attests, "[t]his heterogeneous approach to policy making can directly affect patients and clinicians because they are left to interpret mixed messages from lawmakers about the safety and efficacy of medical cannabis use." The AAFP's position paper on "Marijuana and Cannabinoids: Health, Research, and Regulatory Considerations" acknowledges the burgeoning evidence base regarding these substances' potential medical benefit while also cautioning against their established harms. A 2015 AFP editorial, "Effectiveness, Adverse Events, and Safety of Medical Marijuana," affirms both benefits and harms while calling for reclassification of cannabis as a schedule II drug by the US Food and Drug Administration (FDA) to permit more rigorous outcomes-based research. 

Patients will doubtless continue to inquire about medical cannabis and cannabinoids while we await more definitive evidence; for those clinicians practicing in states where they are an option, discussing the balance of known benefits and harms can help patients make an informed decision. This AFP By Topic on Chronic Pain provides overviews of additional therapeutic options to consider, and stay tuned for "Cannabis Essentials: Tools for Clinical Practice," coming in next month's issue of AFP.

Monday, November 15, 2021

Reassessing race-based clinical prediction tools

 - Kenny Lin, MD, MPH

Five months ago, AFP published Dr. Bonzo Reddick's editorial "Fallacies and Dangers of Practicing Race-Based Medicine." In this editorial, Dr. Reddick reviewed the limitations of several commonly used clinical prediction tools that employ race as a biologic variable rather than recognizing it as a social construct. For example, he pointed out that the American College of Cardiology / American Heart Association Pooled Cohort Equations (PCE) predict that "a 40-year-old White male smoker has a lower cardiovascular risk than a 40-year-old Black male nonsmoker," or put more bluntly, "being a Black man is more dangerous than smoking." Since then, researchers and policy makers have made considerable progress in addressing the inappropriate use of race in medical decision making.

A Curbside Consultation in the September issue introduced a multiracial patient who is confused by the need to identify as African American, White, or Other so that his clinician can evaluate the appropriateness of statin therapy. If White, his estimated 10-year cardiovascular disease (CVD) risk would be 5.8%; if African American, it would be 17.7%. Similarly, a preprint study using thousands of hypothetical and actual patients concluded that large differences in PCE estimates in Black versus White persons with identical risk factor profiles would have the practical effect of "introduc[ing] race-related variations in clinical recommendations for CVD prevention." Until new cardiovascular risk prediction models are developed that omit race, Drs. Mara Gordon and Isha Marina Di Bartolo suggested that physicians exercise caution when using race as a marker of genetic ancestry; consider alternative approaches to risk stratification; and use social determinants of health as an alternative to demographics.

Turning from the heart to the kidneys, including race in the estimation of glomerular filtration rate (eGFR) has the effect of increasing a Black person's eGFR relative to a White person's with the same serum creatinine level. Consequently, Black patients with chronic kidney disease become eligible for kidney transplants nearly two years later than their White counterparts. Underlying this point, Glenda Roberts, a patient representative to a National Kidney Foundation and American Society of Nephrology Task Force that recommended implementing a refitted eGFR calculation that does not include race, observed in a recent opinion piece that though she self-identifies as Black, learning from a DNA analysis that her ancestry was only 48% African (making her, technically, White) would have gotten her on the transplant list sooner! The Chronic Kidney Disease Epidemiology Collaboration has published new eGFR equations that omit race and incorporate serum creatinine and cystatin C.

A 2007 calculator for predicting the likelihood of a successful vaginal birth after cesarean (VBAC) delivery that includes race-based correction factors for African American and Hispanic women was later challenged for promoting disparities in cesarean rates. Earlier this year, researchers from the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units Network unveiled a new VBAC calculator without race variables that has excellent calibration and a similar area under the receiver operating characteristic curve as the previous calculator.

Further work remains to be done. The Agency for Healthcare Research and Quality (AHRQ) posted draft Key Questions for a future systematic evidence report on the impact of clinical algorithms on racial disparities in health and health care. Another AHRQ-funded methods report on racism and health inequities in clinical preventive services and guideline development supported the U.S. Preventive Services Task Force's proposed changes to its recommendation processes to mitigate the effects of systemic racism.

Monday, November 8, 2021

How common is remission of type 2 diabetes?

 - Jennifer Middleton, MD, MPH

Perhaps your patients with type 2 diabetes have also asked you if it's possible to "cure" their diabetes. The only method with an evidence base of doing so to date has been bariatric surgery, but a new study suggests that achieving remission from type 2 diabetes may be more common than previously thought. Using a national registry that included 99% of all persons in Scotland with a type 2 diabetes diagnosis, this study's authors examined hemoglobin A1c values throughout the 2019 calendar year and found that 4.8% decreased their A1c below 6.5%.

In this cohort of over 162,000 persons, the study authors identified several differences between the persons who achieved remission and those who did not:

Key differences in characteristics of people in remission in 2019 compared to people who were not in remission in 2019 were older age (70% of people in remission were aged ≥65, compared to 54% of people not in remission); greater weight loss between diagnosis of diabetes and 2019; lower proportions with previous prescriptions of GLT [glucose lowering therapy] (25% of people in remission had been prescribed GLT compared to 84% of people not in remission); lower mean HbA1c at diagnosis...; and higher prevalence of previous history of bariatric surgery (although overall numbers of people with a history of bariatric surgery were small). 

The authors hypothesize that "[i]t is possible that older people were diagnosed with diabetes with HbA1c values closer to diagnostic thresholds or after minor weight gain, and, therefore, only minor decreases in HbA1c or minor weight loss might be more likely to result in remission than among younger people.It's not surprising that patients who were able to lose weight (those in remission lost an average of 6.5 kg, or about 14 pounds) and/or who had lower A1cs to begin with were more likely to achieve remission. The lower prescriptions of glucose-lowering medications in the remission group likely relates to their overall lower A1cs to begin with. Bariatric surgery has already been demonstrated to help persons with type 2 diabetes achieve remission; a 2020 study found that nearly half of persons with type 2 diabetes achieved sustained remission after gastric bypass, though only 488 persons in the 2019 Scottish cohort had a history of bariatric surgery. 

The American Diabetes Association (ADA) released guidelines last month defining "remission" as an A1c < 6.5% "measured at least 3 months after cessation of glucose-lowering pharmacotherapy." They further recommend that:

  • A1c testing occur at least annually to confirm continued remission
  • Continued regular screening for retinal disease
  • Continued regular screening for kidney disease
  • Continued assessment and treatment of cardiovascular disease risk factors
Little patient-oriented outcomes that matter (POEM) data exists to back these recommendations. The guideline authors do cite this study demonstrating worsening of diabetic retinopathy in persons who achieved diabetes remission after bariatric surgery, though it's unclear whether the abrupt drop in blood glucose levels after surgery contributed to this worsening as compared to just continued retinopathy disease progression.

This Scottish study provides at least some sense regarding those persons more likely to achieve type 2 diabetes remission: older age, lower A1c to begin with, and able to sustain at least 6.5 kg of weight loss. You can read more at the AFP By Topic on Diabetes: Type 2, which includes a wealth of information on screening, prevention, and treatment.

Tuesday, November 2, 2021

Neonatal abstinence syndrome is on the rise

 - Kenny Lin, MD, MPH

The opioid epidemic accelerated during the COVID-19 pandemic, with the Centers for Disease Control and Prevention estimating that more than 93,000 people died from opioid-related overdoses in 2020, a 30 percent increase over 2019. As more pregnant patients have been using opioids, rates of neonatal abstinence syndrome (NAS) have also been on the rise, nearly doubling between 2010 and 2017. Family physicians who care for newborns will increasingly be called on to manage this syndrome. In an editorial in the September issue of AFP, Drs. Roschanak Mossabeb and Kevin Sowti reviewed key points in treatment of NAS, including a low-stimulation environment, skin-to-skin contact, frequent breastfeeding, and opioid therapy when indicated. They emphasized that involving the mother in the care plan is essential to achieving the best outcomes:

Mothers should be viewed as medicine for their infants; by spending time together, infants will likely need less pharmacologic treatment, hence a shorter hospital stay and decreased hospital costs. In addition, strengthening the mother-infant bond may reduce postpartum depression and improve maternal stress response.

Unfortunately, for a variety of reasons mothers and newborns with NAS are often separated after being discharged home. A recent county-level analysis in Health Affairs found that national increases in NAS are associated with increases in placement of infants in foster care: "every one diagnosis ... per ten births was associated with a 41 percent higher rate of infant foster care entry." Infants residing in rural counties were more likely to be placed in foster care than those residing in urban counties.

A quality improvement collaborative in Colorado hospitals aimed to standardize care of opioid-exposed newborns by implementing the Eat, Sleep, Console model. Study results showed that while hospital length of stay and pharmacologic therapy use decreased for all mother-infant dyads during the study period, these positive effects were delayed in mothers who self-identified as being of Hispanic ethnicity. Racial differences in treatment and outcomes have also been observed in studies comparing Black and and White newborns with NAS. However, a critique of two of these studies cautioned physicians against conflating racial disparities with genetic differences in treatment requirements, noting that implicit bias and racism is more likely to explain the disparities than biologically-based explanations.