Type-2: The Genetic Reliance

Disclaimer: This contains science related subject matter from various sources, however (despite studying bachelors in biology) I am not a doctor or an expert in this area. The evidence for this has been obtained from reliable sources.

When someone finds out that I'm diabetic, often the first question they ask is: 'Type1 or Type 2?' with my response being type 1. Following this they often attempt to console me with comments like 'oh right so it wasn't your fault' or 'so you inherited it?'. Sometimes feel quite offended when I hear this, with a lot of people assuming that type 1 is primarily uncontrollably inherited and type 2 being a disease that is purely due to lifestyle, when this isn't true.

Many consider the rise in the number of type-2 diabetics as a result of an increase in seditary and glutinous lifestyle throughout the population i.e. less exercise and higher food consumption. Although there is a degree of truth to this, the whole truth may not have been as publicly explained.

The obesity epidemic which is thought to parallel the rise in diabetes helps predict that the number of diabetics will rise from 171million to 366 million in 2030! That's crazy numbers!

Despite having stated that type-2 diabetes has a strong genetic reliance, the mechanism by which this occurs still remains fairly elusive. However there are a number of gene candidates that contribute to a multifaceted genetic picture. Type-2 diabetes has a wealth of evidence to support its genetic origin, some argue, even more so than type-1 diabetes:

  1. Prevalence in varied ethnic groups: The prevalence of type-2 diabetes varies among populations from 2% among caucasians in Europe to 50% among Pima Indians in Arizona. The substantial variation amongst different ethnic groups is in support of the idea that genetic factors contribute to the predisposition.
  2. Aggregation amongst family: Despite families sharing environments and culture etc, familial aggregation shows strong evidence for genetic contribution. Especially considering that there is a 4-fold increased risk for type-2 diabetes in a sibling of a diabetic compared with the general population.
  3. Twins!: Twin studies reveal that there is a high consistency of mono zygote (same egg - same genes) diabetics as opposed to dizygote (2 separate eggs and therefore increase in different genes). These studies provide pretty compelling evidence of the genetic component of type-2.
  4. Inheritance of diabetic-like traits: insulin sensitivity and insulin secretion are known to deteriorate in type -2 diabetes. However both of these 'traits' are known to be present in non-diabetic but genetically identical twins born from a diabetic parent or descendant from a diabetic.

Main source: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1526773/

Lots of people will have some thought on particular disease's and possibly even attribute some individual blame, but no one really deserves disease… it just happens! The most important thing is dealing with the aftermath!! (Wow…can't believe I'm going to leave that last bit in)

Please comment, like, share and visit my Blog!

This is an old topic here. My opinion: It's very complex. Of course genetics are a piece of the puzzle. But there has been a lot of research recently that indicates Insulin Resistance happens first, followed by weight gain and a dx of T2.

As to fault...Never. T1, T2, LADA, etc....they are all disasters requiring a total re-alignment of one's priorities in life......Judith in Potland

PS: Your title is inappropriately provocative. I would recommend changing it if you want an actually intelligent, rational discussion.

Thank you for the article. It is always a good reminder how Type 2 is inherited. You have alot of Type 1 diabetes as well as non diabetics that believe all the hype when it comes to Type 2 diabetes. So thank you again.

It also follows some forms of lymphoma, as my doctor pointed out to me when I was diagnosed. I was not amused, had been in remission for 20 years or so.

Thanks, Judith and others, for your comments. If you haven't read OurValues Statement recently, please do. We do not support comments that place blame on anyone for their condition.

Thanks Judith and Marie for your comments. I was merely referring to those who may place total blame on themselves and providing information counter to that. I wasn't trying to be provocative, just appealing to the right audience, but I definitely see how it can be construed and I'll change it accordingly.
Also thanks Pastelpainter, I wasn't aware that the consequences of lymphoma can lead to diabetes and I've learnt something new today!

The fact that susceptibility to T2 is genetically based is pretty much beyond dispute at this point. Many of the specific genes have been identified. (Jenny Ruhl discusses this specifically, as do many others.)

The hard questions are, of those who are genetically predisposed, why do some develop the disease while millions of others don't? And why the (relatively recent) explosion in numbers? One of the more popular theories at the moment is that environmental toxins are to blame. But the truth really hasn't been nailed down. "Stay tuned for further developments."

Personally, I wasn't aware of the genetic susceptibility of T2 until coming to university and learning about the condition. I'm fairly sure the relative recent increase has been put down to obesity which increases insulin resistance and increases metabolic load of beta-cells, increasing the risk of pancreatic cell failure. However, as you say this may not have been irrefutably been proven.
I'd really like to know the specific genes involved if you know of a good review? Thanks for commenting!

Obesity as the cause is pretty much the traditional belief. Recent research is beginning to cast doubt on it. It may be that obesity is a result of the syndrome that leads to diabetes, not a cause of it. Opinion is beginning to change.

I was totally unaware of this… That's interesting, would you be able to point me into some of the research please? like a published paper or a website?

The articles are out there, you can research it in as much depth as you have time for. But here is a good place to begin:

Peter Attia Presentation

Thanks, I appreciate this.