Year: 2024

International Diabetes Federation has just released a new Position Statement that indicates that an oral glucose tolerance test performed at 1-hour after a glucose load is more effective in screening at-risk individuals for prediabetes and type 2 diabetes than a 2-hour Oral Glucose Tolerance Test (OGTT). 

The International Diabetes Federation is a non-profit umbrella organization of more than 240 national diabetes associations from 161 countries including the United States (represented by the American Diabetes Association), Canada, Australia, as well as many countries in Europe, Asia and Africa. This global reach means that the IDF’s reports and recommendations have significant international implications.

This international Position Statement provides the evidence to support the practice of requisitioning a 1-hour post load glucose test in place of 2 hour Oral Glucose Tolerance Test to diagnose prediabetes and type 2 diabetes in at-risk individuals.

For physicians who prefer to choose to continue to order a 2-hour Oral Glucose Tolerance Test, this new Position Statement provides support for adding an additional extra assessor at 1-hour, something I have asked for over the last several years based on existing evidence. 

Prediction of Risk of Type 2 Diabetes

The new Position Statement highlights that a 1-hour post-load plasma glucose level of 8.6 mmol/L (155 mg/dL) or higher during in people with normal glucose tolerance strongly predicts the development of type 2 diabetes as well as various complications such as micro- and macrovascular issues, obstructive sleep apnea, metabolic dysfunction-associated fatty liver disease, and death in individuals with risk factors. The recommendations are for  individuals with 1-hour plasma glucose of 8.6 mmol/L (155 mg/dL) or higher to be prescribed lifestyle intervention and referred to a diabetes prevention program.

Diagnosis of Type 2 Diabetes

The Position Statement indicates that a  1-hour post-load plasma glucose level of 11.6 mmol/L (209 mg/dL) or higher confirms a diagnosis of type 2 diabetes and recommends that a repeat test be conducted to confirm the diagnosis of type 2 diabetes and once confirmed, to refer the individual for treatment.

Benefits of the 1-hour Post-Load Glucose Test

The Position Statement indicates that the 1-hour post glucose load test;

1. 1. shows glucose dysregulation earlier than the 2-hour post glucose load test
   2. provides an opportunity to avoid misclassification of glucose status if fasting blood glucose or HbA1c are used alone.
   3. predicts diabetes and associated complications including death in populations of different ethnicity, sex and age
   4. allows for early detection in high-risk individuals which enables the ability to provide intervention to prevent a progression to type 2 diabetes.

Conclusion

The conclusion of the International Diabetes Federation Position Statement is that there is strong evidence to support redefining current diagnostic criteria for prediabetes and type 2 diabetes to include testing at 1-hour post glucose during an Oral Glucose Tolerance Test.

Final Thoughts

There is strong evidence for the use of a 1-hour post glucose load test to diagnose or rule out prediabetes or type 2 diabetes in at-risk individuals.

Most significantly, use of the 1-hour post glucose load test allows for early detection and provision of dietary and lifestyle intervention support to prevent the progression to type 2 diabetes. 

To your good health,

Joy

 

You can follow me on:

Twitter: https://twitter.com/lchfRD
Facebook: https://www.facebook.com/BetterByDesignNutrition/

Reference

 

1. Bergman M,  Manco M., Satman I., et al, International Diabetes Federation Position Statement on the 1-hour post-load plasma glucose for the diagnosis of intermediate hyperglycaemia and type 2 diabetes, Diabetes Research and Clinical Practice, Vol. 209, 111589, March 6, 2024 https://doi.org/10.1016/j.diabres.2024.111589

 

Copyright ©2024 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.

 

 

If you are considering having a DEXA bone density scan to assess your risk of osteoporosis, where you have it done will significantly impact the accuracy of the results, and whether they will provide you with the information you want.

While dual-energy X-ray absorptiometry (DEXA) bone density scans are considered the gold standard for assessing bone mineral density (BMD), it is important to note that there is a large difference in the accuracy of DEXA scans obtained from non-accredited imaging centers offering bone density scans as a service, and facilities specializing in bone densitometry (the clinical assessment of bone density). An accurate scan enables doctors to rule out or establish a diagnosis and provides opportunity for timely treatment recommendations, including dietary and lifestyle modifications.

To illustrate the difference, the first part of the article will explain the standards for accredited facilities, and then contrast them to non-accredited imaging centers. This comparison will underscore the differences between the two.

Accredited Facilities for DEXA Bone Density Scans

For bone density scan data to be reliable in ruling out or diagnosing osteopenia or osteoporosis, it’s important that the scans are conducted by a trained bone densitometry technologist, in a facility that adheres to accreditation standards established by the International Society for Clinical Densitometry (ISCD), and in Canada, by the local College of Physicians and Surgeons of the province. Finally, the scans must be reviewed by a Radiologist, a doctor who specializes in medical imaging before a report is generated.

In British Columbia, the accreditation of bone densitometry facilities as well ensuring that bone densitometry technologists have the appropriate training is overseen by the College of Physicians and Surgeons of British Columbia (CPSBC). They operate the Diagnostic Accreditation Program (DAP), which ensures the quality and safety of a range of diagnostic services, including DEXA bone density scans. The DAP not only verifies that a facility meets the necessary quality standards but ensures that they consistently maintain those standards.

Accredited facilities must adhere to the Accreditation Standards for Diagnostic Imaging from the College of Physicians and Surgeons(1). This comprehensive 312 page document contains imaging standards for x-rays, mammograms, ultrasounds, MRIs , with the standards for bone densitometry beginning on page 274. These standards ensure the quality and safety of bone density scanning procedures.

These standards also outline that bone densitometry facilities must have a Medical Director overseeing operations, and that bone densitometry technologists performing scans must either be certified with the International Society for Clinical Densitometry (ISCD), or have obtained 12 Continuing Medical Education (CME) credits in bone densitometry. Additionally, technologists in accredited facilities are mandated to regularly update their knowledge by acquiring 24 CME credits in bone densitometry every three years.

Summary of the Accreditation Standards for Diagnostic Imaging for Bone Densitometry

The bone densitometry section of the Accreditation Standards for Diagnostic Imaging (1) consists of ten pages of standards, including;

• • patient preparation for the exam
  • standard imaging procedure protocols to ensure that the examination is appropriate for its intended use in clinical decision making
  • ensuring that current and accurate medical records are kept for each person
  • that diagnostic reports are in a standardized format and provide comprehensive and necessary information for clinical decision making / interpretation 
  • safe operation and maintenance of equipment
  • acceptance testing for equipment to ensure it is tested prior to use, and  quality assurance programs to ensure that the required quality is attained

These standards provide additional mandatory requirements and best practices that supplement the accreditation standards established by the International Society for Clinical Densitometry (ISCD) (2).

Below is the first of the ten pages of standards (this page is on patient preparation).

These standards require that the following information be collected before a bone density scan takes place.

(1) taking clinically relevant medical history, including family history, prior fractures, bone trauma, surgery, chronic illness, and any relevant medication that may affect bone density (such as corticosteroids, or thyroid medication),

(2) ensuring that the person has not had any procedures such as a barium x-ray or radionucleotide study that can affect the results,

(3) assessing whether the person has arthritis, deformity or other degenerative changes that can affect measurement,

(4) ensuring the person hasn’t had any implants in the area being assessed, such as a hip replacement,

(5) that a qualified physician is involved in assessing any interference or contraindications,

(6) review of previous bone density scans to determine if a specific site should be excluded from the current scan,

(7) patient height and weight are accurately measured at the time of examination.

None of this, or any of the other 9 pages of standards are required to be followed in an imaging center that provides bone density scans as a service. 

Imaging Center Providing DEXA bone density scans

Imaging centers that provide DEXA bone density scans as a service are business, and are not clinically regulated.  There are no physicians or radiologists involved. These business are not required to meet the international standards of the International Society for Clinical Densitometry (ISCD), or local clinical standards outlined above.

While these centers need to assess height, a construction tape measure attached to the wall with tape may be used, instead of a stadiometer.

Weight may not be asked but rather calculated from the results of a whole body composition scan performed at the same time.

Questions about personal medical history, family medical history, risk factors, medications or procedures that could affect results will be limited.

Image Quality

In accredited facilities, rigorous standards are in place to ensure high image quality, as all scans undergo review by a radiologist prior to report generation.

Images are required to be clear and well defined, such as the top pair of images from HealthLink BC (3). 

Images from imaging centers, such as the pair of images on the bottom often lack the contrast and definition which limits their usefulness.

 

Measurement Accuracy – hips

For hip scans to be useful in diagnosing osteoporosis, it is essential that the neck of the femur (hip bone) is measured at the narrowest part (4), such as the image on the far right (4).

The image on the left from an imaging center does not measure the neck of the femur at the narrowest part, and as illustrated in the middle image, the narrowest part is to the right of where it was measured.

Measurement Accuracy – spine

Spinal images from accredited facilities (left photo from (4)) are clear, and show equal amounts of soft tissue on either side of the spine. In addition, the height of each vertebrae is roughly the same height, with markers in the disk space (4).

   

The image on the right from an imaging center is not clear and has little contrast. It does not show equal amounts of soft tissue on either side of the spine, and the height of each vertebrae varies considerably.

Finding an Accredited Facility

In British Columbia, a full list of accredited diagnostic imaging facilities in the province is available on the College of Physicians and Surgeons web site (5).

The International Society for Clinical Densitometry (ISCD) has a searchable list of accredited facilities by country, as well as US states and Canadian provinces.

The College of Physicians and Surgeons in your province or state may also have a list.

Final Thoughts…

For data from a DEXA bone density scan to be reliable and useful for ruling out or diagnosing osteopenia or osteoporosis, it needs to be performed at an accredited facility.

This can be compared to the difference between home lab test testing and lab tests. While at-home blood testing kits are available to screen for different conditions, diagnoses of a medical condition requires blood tests from an accredited laboratory that are reviewed and assessed by a physician.

If you want to have a DEXA bone density scan to assess your risk of osteoporosis, then speak with your doctor to get a referral to an accredited facility.

How I Can Help

If you have been diagnosed as being at risk for osteoporosis, or have been diagnosed with osteopenia or osteoporosis, implementing appropriate dietary and lifestyle changes can be beneficial.  Please let me know if you would like some support.

DEXA Bone Density Scans are the gold standard for assessing the quality of the inside of bone, and determining whether a person has osteopenia or osteoporosis. More on those scans, soon.

A DEXA Body Composition Scan is designed for assessing the amount of body fat and the distribution of that fat, yet often come with a report that includes “bone mineral density” information. It is essential to understand that “bone mineral density” on a DEXA Body Composition Scan is estimated, not measured. 

This article is about the DEXA Body Composition Scan and what information it reliably provides.

NOTE: (February 14, 2024) If you are thinking of having a DEXA Body Composition Scan, be sure the facility you choose is accredited by the College of Physicians and Surgeons in your area.  More on this in the next article!

DEXA Body Composition Scan

The DEXA Body Composition Scan measures

(a) total amount of fat mass in grams, and

(2) total amount of Lean Body Mass plus bone, in grams.

It does not measure bone mass, but adds both lean body mass and bone mass together. This is important because reports that often accompanying DEXA Body Composition Scans include information about “bone mineral density”, but this information is estimated, rather than assessed. 

The DEXA Body Composition Scan reliably indicates how much total fat someone has, and the distribution of that fat over the body. It does not differentiate between sub-cutaneous fat (the fat under the skin) and visceral fat (the fat around the organs) which is associated with increased health risk.

Since fat mass is what is being directly evaluated in a DEXA Body Composition Scan, the total amount of body fat determined by this method is accurate.

DEXA Body Composition Scan Data of Fat and Lean 

Below are two pages from a DEXA Body Composition Scan report. 

This above page from a DEXA Body Composition Scan report is mostly related to what it assesses directly, which is Total Fat Mass in grams, and Lean Body Mass plus bone in grams, and evaluates the distribution of that fat.

While a DEXA Body Composition Scan does not differentiate between subcutaneous fat and visceral fat, the report indicates “Estimated Visceral Adipose Tissue (fat)” in the table of adipose (fat) indices. It is important to note that visceral fat is not assessed, but estimated. 

DEXA scanners (both GE and Hologic brands) have the National Health and Nutrition Examination Survey (NHANES) data integrated into their software, this which enables them to generate Z-scores for total amount of fat in grams, as well as localized Z-scores for fat in arms, legs, and trunk (1).

Z-scores compare the an individual subject’s results to those of an aged-matched population, and since a DEXA Body Composition Scan measures total fat directly, the z-score in this report for adiposity (fat) is valid.

T-scores compare an individual’s results to how many standard deviations it is from the results of a 30-year old young adult, and since a DEXA Body Composition Scan measures total fat directly, the t-score for adiposity (fat) is also valid.

DEXA Body Composition Scan Data on Bone Mineral Density and Bone Mineral Composition

This is where reports that may be provided with a DEXA Body Composition Scan can get really crazy.

A DEXA Body Composition Scan does not differentiate between Lean Body Mass as muscle and bone, so any information about “bone mineral density” and “bone mineral composition” is based on estimations!  

Since there is no measurement of bone mass in grams separate from Lean Body Mass (muscle),  z-scores for “Bone Mass Density” from a Whole Body Composition Scan make no sense.  This is a comparison of estimated bone data to actual data from an aged-matched population! 

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Have a look at the table below from a 55 year old woman whose DEXA Body Composition Scan report indicates that she had osteoporosis based on estimated bone density numbers. Without having a DEXA Bone Density Scan, of both hips and lower spine she really doesn’t know if she has osteopenia or osteoporosis or not. A DEXA Body Composition Scan is designed to assess fat mass and the distribution of that fat, not bone.

Final Thoughts…

If you have had a DEXA Body Composition Scan and been told that you have osteopenia or osteoporosis remember that this is based on estimates of total amount of bone, and not actual measurement of bone. In such a case, I would recommend discussing with your doctor having a DEXA Bone Density Scan of both hips and lower spine.

If the DEXA Bone Density Scan indicates that you meet the criteria for osteopenia or osteoporosis, then meet with you doctor to discuss the results and their recommendations. In some cases, a doctor may recommend medication to keep bone from breaking down too quickly, and/or a program designed by a Physical Therapist to enable you to safely exercise and retain as much of bone mass you still have, while minimizing the risk of fractures. 

Take Away Message

Remember, that estimated data of “bone mineral density” from a DEXA Body Composition Scan is not the same as data from a DEXA Bone Mineral Density scan which is based on direct assessments.

Getting accurate information using the right diagnostic tool is essential.

How I Can Help

If you are an older adult who wants to optimize your diet and lifestyle to retain as much bone mass as possible as you age, I can help.

To your good health,

Joy

 

You can follow me on:

Twitter: https://twitter.com/lchfRD
Facebook: https://www.facebook.com/BetterByDesignNutrition/

Reference

1. Shepherd JA, Ng BK, Sommer MJ, Heymsfield SB. Body composition by DXA. Bone. 2017 Nov;104:101-105. doi: 10.1016/j.bone.2017.06.010. Epub 2017 Jun 16. PMID: 28625918; PMCID: PMC5659281.

 

 

Copyright ©2024 BetterByDesign Nutrition Ltd.

LEGAL NOTICE: The contents of this blog, including text, images and cited statistics as well as all other material contained here (the ”content”) are for information purposes only.  The content is not intended to be a substitute for professional advice, medical diagnosis and/or treatment and is not suitable for self-administration without the knowledge of your physician and regular monitoring by your physician. Do not disregard medical advice and always consult your physician with any questions you may have regarding a medical condition or before implementing anything  you have read or heard in our content.