The Two Pillars of Diabetes Monitoring: HbA1c and SMBG

India may be encountering a silent epidemic of diabetes. Regular monitoring of blood sugar may no longer be just medical advice but a daily support tool for many individuals. Did you know that there are about 10 crore diabetics and another 13 crore with prediabetes? ¹

Many individuals may be unsure about how to best monitor their diabetes day-to-day. For everyday monitoring, home glucometers could be the go-to choice. The HbA1c test, on the other hand, is typically a lab-based assessment that reflects average blood sugar levels over the past few months and is not meant for daily tracking.

However, it is not a matter of one versus the other. Both HbA1c and Self-Monitoring of Blood Glucose (SMBG) may play unique, complementary roles in diabetes management. Understanding their differences—and when to apply each technique in consultation with a healthcare provider—could help avoid harm and support more informed control.

What Is HbA1c?

The HbA1c test, or glycated haemoglobin test, may help assess the average blood glucose concentration over the last 3 months.

Commonly referenced clinical thresholds, such as those from the WHO and RSSDI, include:

• <5.7% – may indicate levels within the normal range
• 5.7% to 6.4% – could suggest prediabetes
  ≥6.5% – may be associated with diabetes; however, diagnosis should always be confirmed by a qualified healthcare provider

Since it reflects blood sugar trends over time, HbA1c is often considered a useful “big picture” measure. It may give patients and clinicians alike an impression of how well blood sugar has been controlled over weeks and months, independent of any one day’s measurement.²

What Is SMBG?

Typical testing times may include (please consult your healthcare provider to personalise these targets):

• Fasting blood sugar first thing in the morning (<100 mg/dL)
• Before and after meals (80 to 130 mg/dL; < 180 mg/dL)
• At bedtime
• During episodes of feeling unwell, dizzy, hungry, or irritable (Check for < 70 mg/dL, which indicates hypoglycaemia requiring prompt treatment)
• Before and after exercising (126-180mg/dl; note that if the reading is lower than 90 mg/dL, it could mean that the blood sugar is too low to exercise safely. Have a snack or glucose products prior to workouts. Avoid dropping below 70 mg/dL)
• Fasting during festivals (maintain fasting or before meal targets, with more frequent checks to ensure safety)
• Night time (or 3am) to check for overnight glucose levels (aim for safe levels consistent with fasting/post-meal targets to catch any hypoglycaemia)
• During illness, travel, or changes in medication (Continue with fasting and post-meal targets and test more frequently, especially before bed and overnight) ³ ⁴ ⁵ ⁷ ⁹ ¹⁰

Unlike HbA1c, which provides a broad average, SMBG may offer context-specific feedback. It could help patients identify blood sugar highs or lows and, in consultation with their healthcare provider, consider timely steps to stay within target ranges.

Why Both HbA1c and SMBG Could Be Essential

While both methods monitor blood glucose, they serve different purposes:

Dependence on HbA1c alone may overlook daily blood sugar spikes and dips that could cause symptoms or contribute to organ stress over time. Conversely, using SMBG alone without long-term monitoring might risk missing persistent patterns, such as chronically elevated or low glucose levels, which may also have serious health implications. It is advisable to discuss the right balance of both with a healthcare provider.

Health professionals may view HbA1c as a long-term forecast that indicates general glycemic control, whereas SMBG could be comparable to measuring ongoing daily glucose fluctuations. These insights may help inform meal choices, insulin dosage adjustments, exercise routines, and stress management, typically in consultation with a healthcare provider as part of overall diabetes care.

Managing blood sugar could also be compared to a cricket over. Say a batsman scores 12 runs in 6 balls. That total score is like your HbA1c. It tells you how things went overall, but it doesn’t reveal how those runs were made.

That’s where SMBG may come in. It’s like a breakdown of the over—for example, 2 + 4 + 0 + 6 + W + 0. You might be able to spot exactly when the batter hit a six or got out. In the context of diabetes, that could mean identifying when your sugar spiked, dropped, or stayed steady, and responding accordingly with guidance from your healthcare provider.

So, HbA1c offers the summary, while SMBG might support daily decision-making around meals, insulin, physical activity, or stress. Together, they may help individuals and their HCPs stay more informed and proactive in managing diabetes.

When Should You Use Each Method? 11

Addressing Common Concerns About SMBG

Adoption of SMBG in India may be limited due to beliefs that blood checks are painful or that they are necessary only for individuals on insulin therapy. Some people may also assume that feeling “fine” equates to blood sugar being in control.

However, with the latest technology in glucometers, testing is now typically quick and may feel nearly painless, often requiring just a single drop of blood. Many of today’s devices may easily connect to smartphones, making it easier for users to monitor trends, receive reminders, and readily share results with healthcare professionals.⁶

Establishing a Balanced Monitoring Routine

For most people with Type 2 diabetes, doctors may recommend:

• Testing fasting and post-lunch blood sugar 2–3 times per week if on oral medication
• Testing 2–4 times daily if on insulin therapy
• Testing 1-2 years for those managing diabetes through lifestyle changes or in prediabetes ⁷ ⁸

Even limited SMBG testing may help identify patterns and support treatment decisions that HbA1c alone might not fully capture. Always consult your healthcare provider to personalise a monitoring plan.

Complementary Tools for Effective Diabetes Control

HbA1c and SMBG have different but complementary roles and may be most effective when used together for better management of diabetes. HbA1c may inform long-term decisions regarding treatment, whereas SMBG could enable individuals to respond to daily variations related to meals, exercise, or stress.

Using both approaches may offer patients, caregivers, and physicians a better view of blood glucose control, which could support efforts to reduce the risk of complications.

It may be helpful if the attention shifts away from deciding between either tests, and towards realising when and how frequently to apply both within an individualised strategy to diabetes management, ideally guided by a healthcare provider.

References:

1. https://www.thelancet.com/journals/landia/article
2. https://www.ncbi.nlm.nih.gov/books/NBK549816/
3. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/blood-sugar/
4. https://www.cdc.gov/diabetes/treatment/index
5. https://www.mayoclinic.org/diseases-conditions/diabetes/in-depth/diabetes-and-exercise/art-20045697
6. https://pmc.ncbi.nlm.nih.gov/articles/PMC4074758/
7. https://www.nhs.uk/conditions/low-blood-sugar-hypoglycaemia/
8. https://diabetes.org/about-diabetes/diagnosis
9. https://www.rssdi.in/newwebsite/RSSDI-Clinical-Practice-Recommendations
10. https://www.mayoclinic.org/diseases-conditions/diabetes/diagnosis-treatment
11. https://link.springer.com/article/10.1007/s13410-018-0677-3

(Disclaimer: The above article is created by our branded content team in partnership with Roche Diabetes Care India Pvt. Ltd. The article is intended for informational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Health Shots does not endorse or assume responsibility for the product, service, or information presented. Readers are encouraged to consult their healthcare professional for medical advice.)