Download FREE Practo app
Get ₹200 HealthCash
Test is very expensive I can't afford
Should I Get Fasting Insulin or C-Peptide or Both?
My HbA1c and random blood sugar levels are normal, but I still have some symptoms, including dry skin, recurring UTIs, unexplained weight loss, and tinnitus.
My doctor recommended two tests: fasting insulin and C-peptide. However, C-peptide is expensive for me.
Should I get only the fasting insulin test first and consider C-peptide later if the result is abnormal? Or are both tests necessary to do together? Alternatively, is C-peptide more important than fasting insulin in my situation?
I would appreciate advice from doctors on which test would be more appropriate.
Answers (29)
𝐒𝐢𝐦𝐩𝐥𝐲 𝐛𝐨𝐨𝐤 𝐲𝐨𝐮𝐫 𝐜𝐨𝐧𝐬𝐮𝐥𝐭𝐚𝐭𝐢𝐨𝐧 𝐚𝐧𝐝 𝐠𝐞𝐭 𝐬𝐭𝐚𝐫𝐭𝐞𝐝 𝐰𝐢𝐭𝐡 𝐲𝐨𝐮𝐫 𝐜𝐚𝐫𝐞.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Didn't find the answer you are looking for?
Talk to experienced doctor online and get your health questions answered in just 5 minutes.
+116
Dear Sir, if your HbA1c and random blood sugar are normal, fasting insulin and C-peptide tests may not necessarily be required routinely. These tests assess different aspects of insulin production and should be selected based on your clinical history and examination. Your unexplained weight loss and recurrent UTIs deserve further evaluation rather than focusing only on insulin levels.
Next Steps
* Consult your physician to review your weight loss, recurrent UTIs, and previous blood reports.
* Discuss whether fasting blood glucose, urinalysis, urine culture, kidney function, and other targeted investigations are appropriate.
* If your doctor suspects an insulin-production problem, ask whether C-peptide would change your diagnosis or treatment before paying for both tests. Neither test should be chosen solely on the basis of cost without considering the clinical indication.
Health Tips
* Maintain adequate hydration and monitor your weight.
* Do not assume that normal HbA1c and random glucose explain all your symptoms.
* Seek prompt medical attention for fever with urinary symptoms, flank pain, blood in urine, or continuing unexplained weight loss.
Kindly consult your physician to prioritize the most appropriate and cost-effective investigations based on your symptoms.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Need few more details for proper understanding of your issue.
You can consult with me online on Practo or whatsapp on eight three one eight four six nine eight eight six for proper diagnosis, conclusion and management
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
First of all, get blood test done for FBS, PPBS,TSH,FT4; urine test for ACR, RE,ME ,CS,
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
If you would like to discuss your concern in more detail, please feel free to contact me on WhatsApp at eight six one nine six six nine nine zero six. Alternatively, you can connect with me through the Practo app for a detailed consultation
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Get a FBS done
And thyroid profile ,urine rm
Next Steps
Consult me
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
First of all we have to test some more basic and important tests after that we can decide anything else like this.
Please go for these test -
S. TSH,T3, T4
Urine R/M/E
RBS
S.calcium,phosphate,vitd3
If you have any more complaints please provide every little information about you.
Please consult with report.
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Consult
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Do the following:
1. Fasting blood Sugar
2. Postprandial sugar
3. HBA1c
If all three are normal then you do not need any test for diabetes.
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Normal HbA1c and random blood sugar are reassuring, but unexplained weight loss and recurrent UTIs warrant further evaluation.
I would recommend consulting before choosing either test, as the appropriate investigation depends on your symptoms and clinical examination.
Depending on your history, repeat blood glucose testing, urine examination, thyroid function tests, and renal function tests may also be appropriate.
Please don't delay evaluation of unexplained weight loss and recurrent UTIs.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Detail history required for recurrent UTI. Urine Culture and sensitivity test should be done. If your HbA1c level is normal, fasting glucose level should be done. And other relevant test should be done as per advice for recurrent uti.
Di consult and proper follow up needed.
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
As such you are young, Hba1c is normal, chances of diabetes are very less. Get urine microscopic, culture, thyroid function tests, cbc, done to exclude any other reason for your symptoms.
C.peptide levels measurement is slightly more accurate tha fasting insulin levels.
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
These test not required.
I
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
With normal HbA1c and random glucose these tests are not necessary please book a consultation with me to review your symptoms and reports so we can prioritise only the investigations that are necessary
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
kindly do connect and consult with me for better treatment plan and advice on your case via PRACTO app
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Das Kashyap Dinesh
General Physician
2 yrs exp
Surat
Hello,
If your HbA1c and blood glucose levels are normal, fasting insulin and C-peptide are not routinely required together. The choice depends on the clinical suspicion and what your treating physician is trying to establish.
- Fasting insulin: May be considered in selected cases, but it is not routinely recommended for diagnosing insulin resistance.
- C-peptide: Helps assess endogenous insulin production, particularly when there is uncertainty about the type of diabetes or insulin secretion. It is not a routine screening test for diabetes in someone with normal glucose levels.
Given your symptoms of unexplained weight loss and recurrent UTIs, I would recommend an in-person consultation to evaluate the cause rather than proceeding directly with either test. Your doctor may consider repeat blood glucose or HbA1c, urinalysis and urine culture, renal function, and other investigations according to your history and examination.
My suggestion: Discuss with your treating physician whether either test would change your management before spending money on them. Seek prompt evaluation if the weight loss is continuing or the UTIs are recurring.
Hope this helps.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Somen Singh Naharawat
General Physician
2 yrs exp
Jaipur
If you can’t afford c-peptide you should focus on your daily diet and daily routine do brisk walking in the morning and don’t eat sugar or sugar added food or for further info you can consult from me
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Gaurav Jaiswal
General Physician
7 yrs exp
Jhansi
Avoid fried and spicy food .
Water intake more
Green leafy vegetables more
Fiber meal
Walk
Do connect and consult
Will help you
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Vetsa Sri Krishna Chaitanya
General Physician
7 yrs exp
Rajahmundry
Need a few more details please consult for further evaluation and treatment
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Praful Mahamuni
General Practitioner
20 yrs exp
Nagpur
Hello,
This tests are not required
Take Balanced diet.
For diet details and ePrescription consult by practo app.
Thanks.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Nimmi Mulwani
General Physician
10 yrs exp
Ahmedabad
How are your other tests such as CbC, TSH?
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Dr. Pawan Kumar Tiwari
General Physician
6 yrs exp
Varanasi
In your case with normal HbA1c and RBS but weight loss, recurrent UTIs, dry skin and tinnitus, C-peptide is generally more informative than fasting insulin because C-peptide is more stable and directly shows how much insulin your own pancreas is making - low means low reserve as in Type 1/LADA and high means insulin resistance - while fasting insulin is highly variable and mainly used to calculate HOMA-IR for insulin resistance when sugar is borderline high; so if you can only afford one, ask your doctor if you can do fasting C-peptide with fasting glucose instead of fasting insulin, but if cost forces you to start with fasting insulin alone it is acceptable as an initial screen and you can add C-peptide later if it is abnormal or if weight loss continues,
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Dr. Sozab Malik
General Physician
2 yrs exp
Aligarh
Okay, While you are 29 Years old and your HbA1c and RBS are normal so less likely to be Type 2 Diabetes Mellitus. For recurrent UTIs do CBC, Urine microscopic and culture sensitivity. You can do Insulin Fasting but C-Peptide is more reliable and useful for diagnosing Type 1 Diabetes Mellitus.
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Suraj Sharma
General Practitioner
4 yrs exp
Jaipur
Do consult
Answered
Flag this answer
Let others know if this answer was helpful
Was this answer helpful?
YES
NO
Dr. Karan Suneja
General Physician
4 yrs exp
Delhi
Get fasting insulin done
Next Steps
If ur problems are persisting do get the C- Peptide test done .
Health Tips
Consulting to the doctor would be better if your symptoms persist for the proper evaluation
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Dr. Divyansh Jain
General Physician
1 yrs exp
Ghaziabad
Hello,
I understand your concern regarding the cost of investigations.
Fasting insulin and C-peptide measure different aspects of insulin production, but neither is routinely necessary to diagnose diabetes.
Fasting insulin: Primarily used in selected metabolic or hypoglycaemia evaluations.
C-peptide: Helps assess the body's natural insulin production, particularly when distinguishing certain types of diabetes.
Since your HbA1c and random glucose are reportedly normal, neither test is necessarily the first priority.
However, unexplained weight loss and recurrent UTIs deserve further evaluation, even with normal blood sugar reports.
Next Steps
Consult your prescribing physician to clarify why both tests were recommended before spending money on them. Consider a laboratory fasting plasma glucose test, if not already performed, and review your previous HbA1c results. For recurrent UTIs, a urine routine examination and urine culture during symptoms may help identify infection. Unexplained weight loss warrants evaluation, including CBC, TSH, kidney function, and other tests based on clinical findings. If insulin deficiency is specifically suspected, C-peptide with simultaneous blood glucose is generally more informative than fasting insulin alone. However, it should only be ordered when clinically indicated.
Health Tips
My recommendation: Do not spend money on fasting insulin simply as a cheaper substitute for C-peptide. An abnormal fasting insulin result does not automatically indicate that C-peptide testing is required. Both tests are not routinely needed together, and the appropriate choice depends on the suspected diagnosis. Seek prompt medical evaluation if weight loss continues or you develop excessive thirst, frequent urination, fever, or worsening weakness. A targeted, cost-effective investigation plan is preferable to unnecessary testing. Wishing you good health!
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Dr. Anuj Mothsra
General Practitioner
7 yrs exp
Jhunjhunu
Can help you, kindly consult and provide detailed history for proper diagnosis and further management
Answered
Flag this answer
0/1 people found this helpful
Was this answer helpful?
YES
NO
Dr. Ankita Gahlot
Obstetrician
12 yrs exp
Bangalore
With a normal HbA1c and blood sugar, your doctor is likely checking fasting insulin and C-peptide to see how your body is handling insulin before sugar levels actually rise. These two tests measure different things, insulin is the hormone level itself and C-peptide shows how much your own pancreas is producing, so they aren't fully interchangeable.
Next Steps
Fasting insulin is the more affordable first step, so start there. If it comes back high or unclear, go ahead with C-peptide rather than skipping it. Also ask your doctor about thyroid and iron studies, since dry skin, weight loss and tinnitus can point beyond insulin resistance alone.
Health Tips
Please confirm this sequencing with your prescribing doctor before deciding, since they know why both tests were recommended together for you.
Answered
Flag this answer
1/1 people found this helpful
Was this answer helpful?
YES
NO
Articles you may like
Disclaimer : The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding your medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
The question asked on this page is a free question. You can ask a free health question by downloading the Practo app.
Articles you may like
Tell us what's troubling you
Tell us what's troubling you
Disclaimer : The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding your medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.