On July 6, 2021, my fasting blood sugar level was 5.6 mmol/L, or 100 mg/dL.

The laboratory reference ranges were as follows:

Blood Sugar ClassificationBlood Sugar Level (mmol/L)
Normal<5.6
Prediabetes5.6–6.9
Diabetes≥7.0

My previous fasting blood sugar level, tested on April 17, 2020, i.e. more than a year earlier, was normal at 5.1 mmol/L, or 91.8 mg/dL.

On July 6, 2021, I brushed off the borderline fasting blood sugar as some aberration.

The fasting blood sugar test was repeated on my next visit to my gastroenterologist, on October 5, 2021. To my surprise, it was exactly the same as the July 6 reading – 5.6 mmol/L.

I was perplexed and a little disappointed. I had done all I could to lower my blood sugar levels, or so I thought:

  • Regular exercise. Throughout the 3-month period between the clinic visits, I had maintained my long-standing exercise regimen. My Strava records show I had either run or rowed, at moderate intensity, at an average of 26.3 hours per month, or 6.6 hours per week. What my Strava records don’t show is the work I did to strengthen my core.
  • Diet control and modification. My daily diet was/is optimized to manage my irritable bowel syndrome (IBS), not my blood sugar. However, my diet was/is lean and I couldn’t see how I could easily lower my carbohydrate intake safely. I decided to keep my consumption of complex carbohydrates (mainly steamed brown rice) the same while being careful about the amount of simple sugars, e.g. fruits, table sugar (in my coffee and tea), Coca-Cola, in my diet. While I didn’t reduce my intake of simple carbohydrates, I made a deliberate effort to avoid increasing intake of simple carbohydrates. Other changes were:
    • Consuming more animal protein in the form of chicken or pork, while watching the concomitant fat intake. Excessive fat consumption precipitates my irritable bowel syndrome (IBS) symptoms and fatty/oily foods generally don’t suit my palate.
    • A more restrictive form of intermittent fasting. In view of my weight gain and the possibility of fatty liver, I thought it was prudent to lose some body fat. So, in addition to my regular exercise and already-calorie-limited diet, I extended my daily fast from around 15 hours to 16 or 17 hours.
  • Weight loss. My weight on October 5, 2021 was 67.8 kg – a reduction of 6.3 kg, or 8.5% of my previous total body weight (74.1 kg on July 6, 2021). Most of the weight loss was due to a reduction in fat mass, as opposed to muscle mass. My running and rowing performance had not deteriorated during the 3-month interval between clinic appointments. As a result of the weight loss, my running and rowing power-to-weight ratios, which I am far more concerned about than body weight, body composition or body fat percentage, had even improved. I had refrained from cycling because I was due to have a repeat prostate-specific antigen (PSA) test on October 5, 2021 and I didn’t want anything, including cycling, to affect that test result – I have previously given an account of how cycling had affected my prostate and PSA in Q2 2020.

In summary, over a period of three months, I had continued regular moderate-intensity aerobic exercise (running and rowing), adjusted my diet with the aim of lowering my blood sugar levels, and lost a significant amount of fat mass. From my point of view, I had done everything I could sans drugs to lower my fasting blood sugar level by October 5, 2021.

But there was no change in my fasting blood sugar – 5.6 mmol/L. This level is at the bottom end of the range for prediabetes. If it was only 0.1 mmol/L less, the level would be considered normal.

My HbA1c on October 5, 2021, at 5%, was well within the normal range (<6.1%).

I did not undergo an oral glucose tolerance test (OGTT).

The parameters of my lipid profile test – total cholesterol, triglycerides, HDL and LDL, total cholesterol to HDL ratio – on July 6, 2021 were all within the laboratory reference ranges for normal.

Risk Factors

I have two risk factors for prediabetes:

  • I am over age 45
  • My father was diagnosed with Type 2 diabetes, which was treated with antidiabetic medications.

On the other hand, my lifestyle would be considered healthier than most people’s by a fair margin.

My waist measures 31 inches (or 78.7 cm).

My blood pressure is usually below 140/90 mmHg. My blood lipid profile is normal.

The only medication I take on a regular basis is mesalazine.

I am a lifetime non-smoker.

Symptoms and Signs

Prediabetes is typically not associated with any symptoms. Other than fatigue, which I put down to irritable bowel syndrome, I did not experience any other symptom that might have suggested prediabetes, e.g. polydipsia, polyphagia, weight loss before July 2021, or urinary frequency.

I looked for, but did not find, any skin changes that might have been to due to acanthosis nigricans. I didn’t notice presence of any skin tags. My vision had not altered in the months preceding my July 2021 clinic appointment.

Diagnosis of Prediabetes

Fasting Glucose

The American Diabetes Association’s lower cut-off value for impaired fasting glucose (100 mg/dL) is lower than the World Health Organization’s (110 mg/dL).

Therefore, according to the World Health Organization’s criterion, my fasting blood glucose is still within the normal range. However, fasting glucose level is right on the lower limit of the ADA’s range for diagnosing impaired fasting glucose.

Glucose Tolerance

Without having done a 2-hour oral glucose tolerance test, it is impossible to tell if I have impaired glucose tolerance.

Hemoglobin A1c (HbA1c)

MyHbA1c was within the laboratory normal range.

Conclusion

Based on my borderline fasting plasma glucose level (5.6 mmol/L, or 100 mg/dL) and using the American Diabetes Association’s diagnostic criteria, I am “prediabetic,” in that I am at higher risk of developing diabetes mellitus.

However, at this point in time, it seems that intensifying the lifestyle interventions I have used in the past few months will be excessive and may dramatically affect my quality of life. Therefore, I am pushing on with my existing diet and exercise routine, in the hope that it will improve my fasting plasma glucose level.

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