A strong family history increases susceptibility—particularly for Type 2 diabetes—by influencing how the body produces and responds to insulin. However, understanding this inherited risk acts as an early warning system rather than an inevitable diagnosis. In an exclusive interview on the occasion of World Diabetes Day, Dr Thushanth Thomas, Consultant in the Department of Endocrinology and Diabetes at KIMSHEALTH, Thiruvananthapuram, explains how timely screening, vigilant monitoring, and targeted lifestyle modifications can effectively outsmart genetic predisposition.
Q1. For someone with a strong family history or high genetic risk of Type 2 diabetes, what extra lifestyle steps do you recommend, how much can they lower risk, and how do you weigh them against the possible need for medication? Can strong lifestyle measures meaningfully reduce the need for drugs?
A: A strong family history or high genetic risk increases the risk of Diabetes, but you can modify it through lifestyle changes and early screening. Extra steps that you can take to reduce the risk are: lose at least 5-7% of body weight if you are overweight to maintain a BMI of 18-23
- maintain your waist circumference (< 90 cm in males and 80cm in females),
- do at least 150 minutes of physical activity (eg. brisk walking) every week along with muscle strengthening exercise
- sleep well and avoid tobacco
- modify your diet to smaller portions of white rice and refined flour, no sugary drinks, more vegetables, pulses and whole grains and fewer fried snacks.
With these measures, you can reduce the risk by 58% over 3-4 years, 43% over 7 years and 24% over 22 years of follow-up, as per studies.
Q2. Should people with high genetic risk for Type 2 diabetes start screening earlier or more often? Which tests are most helpful, and at what age or body weight should screening begin? What simple home tests or self-monitoring methods do you recommend to catch early changes?
A: People at high genetic risk should start screening as early as possible (any age) if overweight and have at least one risk factor (having a parent or sibling with Diabetes is one of the risk factors, as is our ethnicity). For everyone else, it should start at 35 years of age.
Children and teenagers who are overweight or have risk factors should be checked from puberty or age 10, whichever comes earlier. If tests are normal, repeat every 3 years. It can be repeated annually if there are 2 or more risk factors. The ideal test is GTT (Glucose tolerance test). If that is not practical, a fasting blood glucose test along with a 2-hour postprandial glucose level also might suffice. Another test which can support the diagnosis is HbA1c. At home, glucometer readings can be used, but the results should always be confirmed by a lab for diagnosis. Other home tests which can be done are checking your weight and waist circumference.
Q3. For people with a family history or genetic markers linked to Type 1 diabetes, how do you approach early monitoring? What warning signs should they watch for, and when should they see a specialist?
A: Routine screening for Type 1 Diabetes Mellitus (T1DM) is generally not performed. While T1DM can run in families, the inherited risk is much smaller than that of Type 2 diabetes. However, anyone with a family history of T1DM who tests positive for one or more diabetes-related autoantibodies should consult an endocrinologist. More importantly, if such an individual develops symptoms suggestive of high blood glucose—such as increased thirst, frequent urination, or lethargy—or experiences unexplained weight loss, abdominal pain, and vomiting, they must seek immediate medical attention.
Q4. Do different genetic risk factors or subtypes of diabetes change the advice you give on prevention or monitoring? How do you personalise recommendations when genetic information is available?
A: Intensive lifestyle changes are the cornerstone of prevention for Type 2 diabetes. While they do not play a major role in preventing Type 1 diabetes or monogenic subtypes like Maturity-Onset Diabetes of the Young (MODY), maintaining a healthy weight is always beneficial if you are overweight or obese. Once a person is diagnosed with any form of diabetes, following the foundational lifestyle, dietary, and exercise measures outlined earlier becomes essential for managing the condition effectively.
Q5. What practical early-warning signs or simple home monitoring methods do you suggest for people with high genetic risk so that prediabetes or early diabetes is caught early? How much can acting on genetic information actually reduce the chance of developing diabetes or its complications?
A: Beyond classic high blood sugar symptoms, early physical and clinical warning signs of diabetes risk include:
a) Increasing body weight and waist circumference
b) Dark, velvety patches of skin over the neck and armpits (acanthosis nigricans) and skin tags
c) High blood pressure and elevated triglyceride levels
d) A history of gestational diabetes mellitus
e) Fatty liver detected on an ultrasound or irregular menstrual cycles in women
Noticing any of these indicators—or experiencing classic symptoms like excessive thirst and urination—should prompt immediate blood glucose testing alongside regular home tracking of weight, waist size, and glucometer readings. Acting early on genetic risk allows for timely diagnosis and intervention; starting treatment early and keeping blood glucose levels as close to normal as possible significantly reduces the risk of long-term diabetes-related complications.
