Episode 54 - A1C - a podcast by Rio Bravo Family Medicine Residency Program

A1C is an easy way to diagnose and monitor diabetes, use and limitations of A1C are discussed with Dr Rodriguez. Vaginal metformin is mentioned as an anecdote which has not been proven to work we remembered Memorial Day. 

Introduction: Vaginal Metformin.  
By Hasaney Sin, MD, and Hector Arreaza, MD.

Today is May 31, 2021.  

There’s a saying that I came across on social media that has always spoken to me which I find relevant to our vocation. “The more I learn, the more I find out I don’t know”. So comes the joys (and challenges) of our chosen career. Case in point, have you ever heard of vaginal metformin? Neither have I, until today. 

There was a randomized clinical trial plan in 2013 at Assuit University in Egypt studying the effectiveness of vaginal metformin for the treatment of polycystic ovarian syndrome (PCOS). As primary care providers, we are very aware of the gastrointestinal side effects of metformin when taken PO. This sometimes prevents compliance with metformin. 

The study at Assuit University was to study the effectiveness of metformin when given vaginally in the effectiveness of treating PCOS, while also decreasing the undesirable side effects of metformin when given PO in hopes of also ultimately improving adherence. Unfortunately, the study was planned to be finished in 2014, but no results have been published thus far[1]. Stay tuned in case there is any update.

Arreaza: I had to do a search because I was very curious too. There is at least one occurrence when vaginal metformin was mentioned, at least in English. It was in an online forum where a doctor recommended vaginal metformin for PCOS to a patient. This has not been evaluated or approved by any organization, so I would not recommend it. You know what would be great? Metformin patches! There you have a business idea guys: The Metfo-patch®. 

This is Rio Bravo qWeek, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California. Our program is affiliated with UCLA, and it’s sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. 

Introduction: Memorial Day. 
Written by Valerie Civelli, MD, read by Steven Saito, MD, and Hector Arreaza, MD

What is Memorial Day? Memorial Day is an American holiday at the end of May to honor the men and women who died while serving in the US military. It has great historical meaning to Americans. It originated from the Civil War which claimed more lives than any other conflict in US history. Civil war ended in 1865.   

A fun fact to know, is that Memorial Day, was originally called “Decoration Day”.  It was 3-years after the Civil war ended, May 5, 1868, that “Decoration Day” was declared as a time for the nation to decorate the graves of those lost in war.  Graves were adorned with flowers and their lives celebrated.  

Maj. Gen. John A. Logan then declared that “Decoration Day” should be observed on May 30th. It is believed that this date was chosen because flowers would be in full bloom across the country. 

The “birthplace” of “Memorial Day” was recognized as coming from Waterloo, New York, because Waterloo was the first to use this term to expand honor and recognition of all US fallen soldiers of war from the Civil War and from World War I. 

In 1971, “Memorial Day” was officially declared a national federal holiday: The National Moment of Remembrance encourages all Americans to pause wherever they are at 3:00 p.m. local time on Memorial Day for a minute of silence, to remember and honor those who have died in service to the nation. If you value your freedom wherever you are, this Memorial Day at 3:00 p.m., pause for a minute to recognize all of our military men and women, both past and present who served and continue to serve our country. We honor every soldier who lost his or her life in any war against America. You are the reason for our freedoms.  You gave the ultimate sacrifice, and we do not take this for granted. 

To all military members who have died at war, we appreciate the privileges we have today because of you. We honor the costly price at which it came.  We remember you. We honor you. We sincerely thank you. Happy Memorial Day everyone! 

___________________________

A1C.

By Hector Arreaza, MD, and Yodaisy Rodriguez, MD.  
 

Definition. 

Glycated hemoglobin (glycohemoglobin, hemoglobin A1c, or just A1c) is a form of hemoglobin that is chemically linked to a sugar. Glucose spontaneously bind with hemoglobin, when present in the bloodstream of humans.

A1C refers to the percentage of glycosylation of the hemoglobin A1C chain and correlates with the average blood glucose levels over the previous 2-3 months from the slow turnover of red blood cells in the body. A RBC lives 120 days.

History of A1C. 

Huisman and Meyering separated glycohemglobin for the first time in 1958. A1c for monitoring the degree of control of glucose metabolism in diabetic patients was proposed in 1976 by Anthony Cerami, Ronald Koenig and coworkers.

A1C was first included in the ADA guidelines as a diagnostic test for diabetes in 2010. Prior to that random glucose or fasting plasma glucose were used for diagnosis.

For diagnosis of diabetes, A1C testing should be done by a technique certified by the National Glycohemoglobin Standardization Program and consistent with the Diabetes Control and Complications Trial reference assay.

A1C levels. 

A1C <5.7% is considered normal, 5.7-6.4% is prediabetes, >6.5% is diabetes.

Of note, other criteria for diagnosing diabetes: Fasting plasma glucose >126 mg/dL, 2-hour plasma glucose > 200, random glucose >200 plus classic symptoms.

In patients with prediabetes, A1C should be tested yearly.

The American Diabetes Association (ADA) has recommended glycated hemoglobin testing (HbA1c) twice a year for patients with stable glycemia, and quarterly for patients with poor glucose control. Use ADA guidelines to assess targets.

Point-of-care A1C (POC A1C): POC is not recommended for screening or diagnosis but it is good for monitoring.

A1C limitations.

There are some limitations to A1C testing, and an incomplete correlation between A1C level and average glucose level in certain individuals.

Nonglycemic Factors That May Interfere with A1C Measurement

Falsely lower A1C: Acute blood loss, Chronic liver disease, Hemolytic anemias, Patients receiving antiretroviral treatment for human immunodeficiency virus, Pregnancy, Vitamins E and C. Patients being treated for iron, B12 or folate deficiency, EPO, chronic hemolysis (thalassemia).

 

Lower or elevate A1C: Hemoglobinopathies or hemoglobin variants, Malnutrition

 

Falsely elevate A1C: Aplastic anemias, Hyperbilirubinemia, Hypertriglyceridemia, Iron deficiency anemias, Renal failure, Splenectomy.

For example, when RBCs have a short life, like in acute bleeding, the A1C is falsely low. On the other hand, when RBCs live longer (history of splenectomy and aplastic anemias) the A1C is falsely elevated. It’s a good idea to do CBC with A1C.

Ethnic groups: Hemoglobinopathies or hemoglobin variants can change A1C levels and may be more prevalent among certain racial and ethnic groups. A1C tends to be higher in some races/ethnic groups: AA, Hispanic-Americans, Asian-Americans.

Other A1C limitations: It gives you an average, patient may be experiencing hypoglycemia alternated with hyperglycemia and result in normal A1C. 

Screening for diabetes.

ADA: Screen for diabetes or prediabetes all asymptomatic adults, according to the ADA, who have overweight or obesity with one or more risk factor (first degree relative with diabetes, high risk race or ethnic group, history of CVD, hypertension, dyslipidemia, PCOS, physical inactivity, severe obesity, acanthosis nigricans), patients with prediabetes (every year), women with GDM (every 3 years), all other patients after 45 years of age. If results are normal, test every 3 years, patients with HIV.

USPSTF: Adults aged 40 to 70 years who are overweight or obese. The USPSTF recommends screening for abnormal blood glucose as part of cardiovascular risk assessment in adults aged 40 to 70 years who are overweight or obese. (Draft: Asymptomatic adults ages 35 to 70 years who are overweight or obese) This is a Grade B recommendation. Clinicians should offer or refer patients with abnormal blood glucose to intensive behavioral counseling interventions to promote a healthful diet and physical activity. 

The USPSTF recommends screening for gestational diabetes mellitus (GDM) in asymptomatic pregnant women after 24 weeks of gestation. This is a Grade B recommendation.

Grade I recommendation (insufficient evidence): Asymptomatic pregnant women, Before 24 Weeks of Gestation. The USPSTF concludes that the current evidence is insufficient to screen for GDM in asymptomatic pregnant women before 24 weeks of gestation.

A1C Targets.

A1C goals can range from 6.5% to 8%. Target is individualized based on life expectancy, disease duration, presence of complications, CVD risk factors, comorbid conditions and risks for severe hypoglycemia. Sometimes your goal can be independent of A1C, for example, your goal can be to avoid complications. As a fun fact, A1C is not used in veterinary medicine.

Conclusion.
By Hector Arreaza, MD. 

Now we conclude our episode number 54 “A1C”, three characters that may not mean much for most people but for patients with diabetes, it is a very important number to remember. Remember to check the A1C in all your patients with poor control of diabetes every 3 months, or every 6 months in patients with good control. A1C has its limitations but it certainly is the best way to assess your patients’ glycemic control. We started this episode by giving you a random report about vaginal metformin, the study was unfinished, and we also reminded you of the importance of remembering our heroes during Memorial Day. Even without trying, every night you go to bed being a little wiser.

Thanks for listening to Rio Bravo qWeek. If you have any feedback about this podcast, contact us by email RBresidency@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. This podcast was created with educational purposes only. Visit your primary care physician for additional medical advice. This week we thank Hector Arreaza, Hasaney Sin, Valerie Civelli, Yodaisy Rodriguez, and Steven Saito. Audio edition: Suraj Amrutia. See you next week!

References:

Vaginal Administration of Metformin in PCOS Patients, U.S. National Library of Medicine, Clinical Trials.Gov, https://clinicaltrials.gov/ct2/show/study/NCT02026869.

 

Office of Public and Intergovernmental Affairs, U.S. Department of Veteran Affairs,  https://www.va.gov/opa/speceven/memday/history.asp, accessed on May 26, 2021. 

 

Pippitt K, Li M, Gurgle HE. Diabetes Mellitus: Screening and Diagnosis. Am Fam Physician. 2016 Jan 15;93(2):103-9. Erratum in: Am Fam Physician. 2016 Oct 1;94(7):533. PMID: 26926406. https://www.aafp.org/afp/2016/0115/p103.html.

 

Standards of Medical Care in Diabetes – 2021, Diabetes Care, January 1, 2021, vol 44 issue supplement 1, https://care.diabetesjournals.org/content/diacare/suppl/2020/12/09/44.Supplement_1.DC1/DC_44_S1_final_copyright_stamped.pdf.

Further episodes of Rio Bravo qWeek

Further podcasts by Rio Bravo Family Medicine Residency Program

Website of Rio Bravo Family Medicine Residency Program