KNOW YOUR FAT…………………YOUR BODY’S FAT!

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I know what many of you are thinking. Oh no! Not another post on “good fats” and “bad fats”, how saturated fat is NOT KILLING you! No, this post is not about dietary fat. I am talking about your body’s natural fat and how your body’s fat distribution decides your health.

Body fat or adipose tissue is not just a mass of fatty material lying around as inert weight. Without going into much details I will summarise a few important features.

  • There are different types of adipocytes that are broadly classified into white, brown, or beige adipocytes.
  • White adipocytes help store energy,
  • Brown adipocytes help in generating body heat (thermogenesis)
  • The function and origin of beige cells is less clear and is under investigation.
  • Adipocytes are recognized as critical regulators of whole-body metabolism.The major ones being lipid metabolism, blood sugar control, regulation of blood pressure, blood clotting and inflammation.
  • Insulin resistance. (More on insulin resistance in other post/video)
  • Fat cells secrete hormones that regulate energy homeostasis in other tissues. Leptin, Adiponectin and Resistin are the important ones.
  • Adipocytes secrete inflammatory substances called adipokines. There are about 50 known ones that are secreted by fat cells.
  • Adipocytes are involved in sex hormone metabolism through the enzyme aromatase. (This is very important in deciding you risk for breast and prostate cancers).
  • Hormone disrupting chemicals (EDC) ,environmental toxins are stored in fat (and they also increase fat store).

WHERE IS THIS FAT (ADIPOSE TISSUE) LOCATED?

Although the amount of total body fat is strongly associated with insulin resistance,heart disease, stroke, diabetes, cancer and dementia,it is becoming increasingly clear that different fat compartments contribute differentially to these risks.

From:Fuster, José J., et al. "Obesity-induced changes in adipose tissue microenvironment and their impact on cardiovascular disease." Circulation research 118.11 (2016): 1786-1807.

Brown Adipose Tissue: This is present mostly around the neck and its main function is in generating  body heat. Newborn babies have more of this fat. It is also called the “good fat”.

Perivascular Adipose Tissue: This is the fat present around blood vessels. It was long thought to have only a supporting role, but is now understood to have a major role in health and disease. It secretes biologically active chemicals and is involved with blood vessel inflammation.

Bone Marrow Adipose Tissue: As the name implies, this is the fat in bone marrows. Not a lot is known about its function yet, but it is probably related to bone mass.

Ectopic Hepatic Lipids: This is the fatty liver (Non-Alcoholic fatty Liver Disease NAFLD) that develops due to consumption of excess carbohydrates-“diabetes of the liver”. It is related to insulin resistance and is a risk factor for diabetes, heart disease and many more diseases. Fatty liver (NAFLD) can progress to NASH (Non-Alcoholic Steatohepatitis), fibrosis, cirrhosis and liver cancer. NAFLD is like an epidemic worldwide.

Subcutaneous Adipose Tissue (SAT) and Visceral Adipose Tissue (VAT): The acronym VAT reminds me of Hindi movies of the seventies where the villain usually drank VAT 69 , the whisky ! Excess VAT, ie the body’s VAT ,is fat that accumulates among the internal organs. This is very distinct from the SAT , which is fat beneath the skin. Excess VAT is related to a whole host of cardiometabolic diseases. Increased belly fat is usually excess VAT. SAT probably has protective functions. The apple-shaped body versus the pear-shaped body!

Epicardial Adipose Tissue: This is the fat present between 2 layers of the heart. I will not discuss all the different types of cardiac fat here, except to mention that excess epicardial fat is associated with many diseases like coronary artery disease (CAD),which is atherosclerotic thickening of the blood vessels supplying the heart, and insulin resistance.

Amongst all the different types of adipose tissue the ones most relevant to health (as far as knowledge goes today) are brown fat,SAT, VAT, liver fat and fat in the heart.

HOW DO YOU KNOW IF YOU HAVE EXCESS FAT IN THESE COMPARTMENTS?

Waist measurement and Waist-Hip Ratio:

As many of you know your BMI is not the best measure of health. This is particularly so for South Asians.This is because many of you are TOFI–Thin-Outside-Fat-Inside or “Skinny Fat”. This means that at a given body weight , you may have a higher body fat percentage than is healthy for you.

 

TOFI–THIN-OUTSIDE-FAT-OUTSIDE

 

KNOW YOUR NUMBERS:
Waist Circumference:

Men: Waist circumference 85-90 cm (34”) or more is unhealthy.

Women: Waist circumference 80 cm (31.5”) or more is unhealthy.

The easiest way to measure this is by measuring your waist size with a tape measure at the level of the belly button.

Waist to Hip Ratio:

Divide your waist circumference by your hip circumference.

Hip circumference: Measure the circumference of your hips at the widest point of your buttocks.

Healthy Waist/Hip ratio : Men 0.90  , Women 0.80.

Blood Tests: (Basic)
  1. Fasting Blood Sugar
  2. Post Meal Blood sugar
  3. Fasting Insulin.
  4. Triglycerides
  5. Hs-CRP
  6. AST,ALT (SGOT,SGPT)
  7. GGT
Weighing Scales :

Weighing scales that show your body fat and lean mass percentage are acceptable measures of health.

Imaging:

Ultrasonography of whole abdomen can detect fatty liver.

Echocardiography: To detect heart function and fat.Currently, there is no consensus on the ‘gold standard’ for quantification of cardiac fat.

MRI: Costs more.

PET, DXA,CT scans: Radiation exposure. I don’t usually recommend these tests only to quantify body fat

SUMMARY

  • If you have belly fat, it puts you at a high risk for diseases like diabetes, heart disease, dementia, cancer.
  • Belly fat relates to insulin resistance.
  • You do not get fat by eating good quality fat. It is very likely that you eat more carbohydrate than is good for you.
  • A recent study called the PURE study in a prestigious journal The Lancet,showed that eating excess carbohydrate , not saturated fat puts you at higher risk of dying.
  • Dietary carbohydrate gets stored as body fat.
  • Know your basic blood numbers. (You will need someone knowledgeable in this field to interpret the numbers. Please remember that “in normal range” is not necessarily optimal).
  • If you are insulin resistant it is very likely that you have fatty liver and higher cardiac fat.
  • Total body weight is not the best measure of health.—Remember TOFI! This means that your skinny friend may not necessarily be healthy!

REFERENCES:

Porter, Stacy A., et al. "Abdominal subcutaneous adipose tissue: a protective fat depot?." Diabetes care 32.6 (2009): 1068-1075.

Dehghan, Mahshid, et al. "Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study." The Lancet (2017).

 

 

 

 

 

 

A DIFFERENT DIABETES: LATENT AUTOIMMUNE DIABETES OF THE ADULT (LADA)

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WHAT IS LADA?

Latent Autoimmune Diabetes of the Adult (LADA) is a type of autoimmune diabetes which shares common features between type 1 and type 2 diabetes.It is also called Type 1.5 diabetes or slowly progressive autoimmune diabetes.The 3 common criteria for diagnosis of LADA are:
  • Adult onset:the age at diagnosis ranges from 15 to 30 years.However, nowadays Type 2 diabetes is being diagnosed in increasingly younger people.The youngest person to be diagnosed with type 2 diabetes is a three year old girl in Texas, USA.
  • Antibody positivity: Diabetes Associated Antibodies (DAA) are usually present in people with LADA.However this may not be quite so clear-cut, given that different laboratories may have different cut-off values.These DAA include antibodies to glutamic acid decarboxylase 65 (GAD 65), insulinoma-associated antigen, islet cell & zinc transporter 8. The commonest is GAD 65 antibody.Antibody levels may fluctuate and the type of positive antibody may change over a period of time.Even a transient increase in autoantibody indicates autoimmunity.
  • Insulin treatment: Arbitrary definition of LADA include a period without insulin treatment of at least six months, but the need to use insulin is usually at the discretion of the physician.

WHY DO YOU NEED TO KNOW IF YOU HAVE LADA?

  • Patients with LADA generally have worse HbA1c levels (measure of 3 month’s average blood sugar) than type 2 diabetes patients.
  • Often they are misdiagnosed as type 2 diabetes.Incorrect treatment will lead to higher loss of insulin producing beta cells of pancreas.
  • Studies have shown that patients with LADA need insulin treatment earlier than those with type 2 diabetes and therefore may need closer monitoring.
  • Patients with LADA have lower levels of C-Peptide. (Connecting peptide is a marker of insulin production by your body). C-Peptide levels influence treatment.
  • The sulphonylurea group of drugs like chlorpropamide,glyburide,glipizide etc which work by stimulating the pancreas to release more insulin, are not the right choice of drugs for people with LADA.
  • Despite greater use of insulin, patients with LADA have worse blood sugar control. Therefore there is something more that needs to be done.
  • When any one autoimmune condition is present, the chances of developing others are high. People with LADA have a higher incidence of thyroid autoimmunity. Hence it is important to screen for other diseases as well.

WHAT IS DIFFERENT ABOUT A FUNCTIONAL AND METABOLIC MEDICINE APPROACH?

In addition to testing for DAA we would look at the following:

  • Gut Health.
  • Gut dysbiosis
  • Intestinal Permeability Dysfunction (Leaky Gut)
  • Vitamin D3 levels
  • Chronic Inflammation
  • Sleep
  • Nutrient Depletion
  • Stress Response
  • Movement/Exercise
  • Test for other autoimmune conditions, particularly thyroid autoantibodies.
  • Risk for heart disease and stroke
  • Check for heart failure.

Should everybody be screened for LADA?

That will depend on your goals.I practice patient-participatory medicine. My duty as a physician is to provide you with correct information and help  you make the best decision for yourself.

You MAY BE INTERESTED IN READING:

Do you have autoimmune diabetes

Predictive Autoantibodies

Vitamin D and Autoimmunity

Ebook on Autoimmunity

REFERENCES
Gambelunghe, Giovanni, et al. "Increased risk for endocrine autoimmunity in Italian type 2 diabetic patients with GAD65 autoantibodies." Clinical endocrinology 52.5 (2000): 565-573.
Priyanka P. Brahmkshatriya, Anita A. Mehta, Banshi D. Saboo, and Ramesh K. Goyal, “Characteristics and Prevalence of Latent Autoimmune Diabetes in Adults (LADA),” ISRN Pharmacology, vol. 2012, Article ID 580202, 8 pages, 2012. doi:10.5402/2012/580202

DO YOU HAVE AUTOIMMUNE DIABETES?

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WHY DO YOU NEED TO KNOW IF YOU HAVE DIABETES AUTOIMMUNITY?

Sonia Kumar (not her real name) a 38 year old mother of two young girls, spent seven frustrating months trying to get her blood sugar under control.She was recommended escalating doses of oral anti-diabetes medications. She was even accused of cheating on her diet!But none of this helped her! It took an astute physician (not me!) to test her for diabetes autoantibodies to find out that she actually had Type 1 Diabetes!

The diagnosis was missed because people often think that Type 1 Diabetes does not develop in adults.

WHAT IS DIABETES?

Diabetes is a group of metabolic diseases with high blood sugar (hyperglycaemia) as the common feature. The high blood sugar results from defects in insulin secretion, defects in insulin action or both. About 20 years ago diabetes was classified into Insulin Dependent (IDDM) or Juvenile and Non-Insulin Dependent (NIDDM) or Adult Onset Diabetes. However, in the last several years it has become apparent that the use of insulin or age at onset could not adequately explain the disease conditions and specify the best treatment plan. Therefore, there is an opinion amongst diabetes researchers that the time has come for a new classification of the disease.

Diabetes develops because of an interaction between genes and the environment. Our genes have not changed in thousands of years,but our environment has.To a great extent this explains the dramatic increase in diabetes over recent years. Some of the influences have originated in the intrauterine environment before a person is born!

Exposure to environmental toxins like BPA have also contributed to the recent epidemic of diabetes.

Developments in the field of precision medicine, ethnicity-specific data and big data along with patient-participatory research will change the management of diabetes for the better.

TYPES OF DIABETES:

(For a medically appropriate classification please check the American Diabetes Association website for “Etiologic classification of diabetes mellitus”).

  • Type 1 Diabetes
  • Type 2 Diabetes (Commonest)
  • Gestational Diabetes (GDM/Pregnancy Diabetes)
  • Maturity Onset Diabetes of the Young (MODY)♣
  • Latent Autoimmune Diabetes of the Adult(LADA)♣
  • Drug Induced Diabetes.♣
TYPE 1 DIABETES

High blood sugar resulting from an absolute deficiency of insulin secretion. Type 1 Diabetes may be

  • Autoimmune or
  • Idiopathic.

Autoimmune Diabetes occurs when the Insulin producing cells in the pancreas are destroyed by an autoimmune process. Autoimmune markers for Type 1 Diabetes, also called Diabetes-Associated Autoantibodies (DAA) are usually present in most of these patients.

Idiopathic—In a small percentage of patients there is Insulin deficiency but no autoimmunity.

Though absolute insulin deficiency is a hallmark of Type 1 Diabetes, about 30 % of people with this condition have insulin resistance as well.

DIABETESASSOCIATED AUTOANTIBODIES (DAA):

  • Glutamic Acid Decarboxylase Autoantibodies (GAD65 or Anti-GAD)
  • Insulin Autoantibodies (IAA)
  • Insulinoma-Associated-2 Autoantibodies (IA-2A)
  • Islet Cell Cytoplasmic Autoantibodies (ICA)
  • Zinc Transporter 8 (ZnT8Ab) Autoantibodies
GESTATIONAL DIABETES (GDM or PREGNANCY DIABETES)

GDM is defined as any degree of glucose intolerance that was first recognized during pregnancy. This definition would include women who had previously undiagnosed Type 2 Diabetes and also those women who developed diabetes for the first time during pregnancy.Asian Indian women are at a very high risk for pregnancy diabetes. Therefore it is very important for them to be screened at the beginning , during mid-trimester as well as in the last trimester.

GDM raises the risk of several complications in both the mother as well the baby. Increased birth defects, increased birth weight, early (preterm) delivery are some of the risks in the babies born of mothers with GDM. The mother is at increased risk of pregnancy high blood pressure and pre-eclampsia and is at a higher risk for developing diabetes later in life. In addition, she is at increased risk for heart disease even if she does not develop diabetes later on in life!

TYPE 2 DIABETES

This is the commonest type of diabetes.Type 2 diabetes includes individuals who have insulin resistance and usually relative insulin deficiency. These individuals may not need insulin treatment to survive. However, use of insulin does not decide the type of the disease. Diabetes Associated Autoantibodies are absent in people with Type 2 Diabetes.

HOW DOES THIS AFFECT YOU?

It is important to keep in mind that adults can develop autoimmune diabetes too! British Prime Minister Theresa May, who was diagnosed with Type 1 Diabetes at age 56 and Sonia Kumar mentioned above were both initially diagnosed as Type 2 Diabetics. However both of them needed insulin therapy to control their blood sugar levels,when they were found to have Diabetes Antibodies.

Sulfonylurea (SU) drugs like chlorpropamide,glyburide,glipizide which work by stimulating the pancreas to release more insulin, are not the right drugs for these people.Use of these drugs in patients with diabetes autoimmunity have shown poor metabolic control and earlier loss of insulin producing beta cells in the pancreas.

A study in apparent long-standing type 2 diabetes found that those with Diabetes Associated Autoantibodies or with low C-peptide did not respond well to glucagon-like peptide 1 (GLP-1) agonist drugs like Liraglutide,Exenatide etc.

People with one autoimmune condition are at a higher risk for other autoimmune conditions as well. Diabetes Autoimmunity has often been associated with thyroid autoimmunity.

NUMBERS TO KNOW

If you have diabetes you obviously know your blood sugar and glycated haemoglobin (HbA1C) levels. In addition the following tests are important for the right treatment:

  • Diabetes Associated Autoantibodies (DAA)
  • C-Peptide ♣ :This  test can indicate how much insulin your body is producing.

(♣ Separate blog posts on these topics later.)

As Dr. Elliott P. Joslin, (who was the first doctor in the United States to specialize in diabetes and the founder of Joslin Diabetes Center) wrote “ . . . unless the physician takes care, he will fall into schematic ways and forget that it is the patient who comes for treatment and not the diabetes. Each is a case unto itself.” 

 

REFERENCES

Mohan V, Usha S, Uma R. Screening for gestational diabetes in India: Where do we stand? Journal of Postgraduate Medicine. 2015;61(3):151-154. doi:10.4103/0022-3859.159302.
Goueslard, Karine, et al. "Early cardiovascular events in women with a history of gestational diabetes mellitus." Cardiovascular diabetology 15.1 (2016): 15.
Leslie, R. David, et al. "Diabetes at the crossroads: relevance of disease classification to pathophysiology and treatment." Diabetologia 59.1 (2016): 13-20.
Brophy S, Davies H, Mannan S, Brunt H, Williams R. Interventions for latent autoimmune diabetes (LADA) in adults. Cochrane Database of Systematic Reviews 2011, Issue 9. Art. No.: CD006165. DOI: 10.1002/14651858.CD006165.pub3.