Monday, October 29, 2007

Planning Guidance for Sustainability

If you are thinking a year ahead, sow a seed,
If you are thinking ten years ahead, plant a tree.
If you are thinking one hundred years ahead,
educate the people.

Kuan Tzu Chinese Poet, c. 500 B.C.

Sunday, October 28, 2007

How to Avoid DKA, Hypos, and Other Side Effects of Feline Diabetes

Ketones are waste products that result from the body's use of stored fat for energy. In a diabetic, any urinary ketones above trace, or any increase in urinary ketone level, or trace urinary ketones plus some of the symptoms above, are cause to call an emergency vet immediately, at any hour of the day. Diabetic ketoacidosis is caused by a lack of insulin or an insufficient amount of insulin.

Hypoglycemia
is dangerously low blood sugar brought on by too much insulin. It can result in seizures, coma, and even death.

These two conditions represent the opposite ends of the diabetic spectrum, from too much insulin to not enough. Managing your cat's diabetes involves navigating between these two potentially lethal side effects. Diet, testing, and regulation are primary considerations in achieving this goal.

  • Feed a low-carb wet diet.
    If your cat refuses to eat wet food, supplement the dry food with cooked meats as you transition away from the dry. See Dr. Lisa's Transitioning Dry Food Addicts to Canned Food for more ideas.

  • Use a human glucometer to test your cats blood at home.
    Hometesting will give you the information you need to determine when a dose needs to be changed either up or down. If you have a good relationship with your vet, you can call and report your test numbers and work together to determine any dosing adjustments. If your vet doesn't support hometesting, join one of the Insulin Support Groups and work with others who have experience with your particular insulin.
    Hometesting video

  • Use the results of your testing to achieve regulation.
    When your cat is first diagnosed with diabetes, your goal is to "regulate" her or his blood glucose, which may take a few weeks or even many months. Eventually you will want to aim for blood sugar levels in the 70 to 200 range. This won't happen right away but by reducing carbohydrates from your cats food and hometesting, you can achieve this goal safely. The well-regulated diabetic cat should look and act the same as he/she did before diabetes. If you have any concerns about your meter reading too low, you can test a non-diabetic cat as your control.

There's no sure-fire method for eliminating all risk of hypos, DKA, and other diabetes-related problems, but you can greatly reduce the risk by learning all that you can. Insulin is a powerful hormone. The more you know about it, the safer your cat will be.

Wednesday, October 03, 2007

Rebound: A Positive Feedback Loop

A positive feedback loop is a cause and effect response that has no self-correcting mechanism. An example of a positive feedback loop is your bathtub. If you turn the water on and let it run to fill, it will continue running until you manually turn it off, even if that means it floods your bathroom.

Counter intuitively, negative feedback loops are self-correcting. An example of a negative feedback loop is your home thermostat. You set it at the threshold you want, and it continually samples the room temperature and makes corrections to maintain the desired temperature setting (threshold).

In feline diabetes, the way a cat's body uses insulin is both a positive feedback loop and a negative feedback loop. When the body gets too much insulin, the liver releases glycogen (stored glucose) to protect against hypoglycemia. That's the negative feedback loop.

When the body receives too much insulin over time, the liver adjusts its threshold upward. For example, instead of recognizing 50 mg/dl (for felines) as a glucose level that is too low and requires intervention through released glycogen, it starts to think anything lower than 200 mg/dl needs adjustment. So the cat's body stops using the insulin effectively and stays in a continuous hyperglycemic state, also called rebound. The negative feedback loop, which is the natural mechanism, is overwhelmed by too much insulin, which in turns creates the unnatural positive feedback loop.

Since there are no tests for rebound, humans too often continue to increase the insulin dosage in order to alleviate the hyperglycemia, causing the liver to set the 'hypo' threshold even higher. So no matter how much additional insulin the cat receives, the response is in the opposite direction than what is expected.

Unfortunately, a cat in rebound is always subject to hypoglycemia since the liver does not have a endless supply of stored glucose/glycogen. When the glycogen runs out, hypo results.

The only way to break a positive feedback loop is to stop feeding it. In feline diabetes, that means reducing the insulin dosage, hopefully before the cat hypos.

Other examples of positive feedback loops:
  • credit card debt (the more you borrow, the deeper in debt you go and the more you need to borrow to cover the debt)
  • hyperactive behavior in a child; the more they over-react, the more wound up they get
  • alcoholism and drug addiction....any addiction

Drought Restrictions

As of October 1, 2007, the OWASA reservoirs are 56% full. According to the state climatologist, La Nina conditions are expected to continue the drought well into the winter months. La Nina is cooler than normal ocean temperatures in the Pacific Ocean that affect weather patterns in North Carolina. There are about 10-12 reliable indicators, but drought prediction is still a nascent science. So while these predictions could be totally wrong; the state climatologist (Ryan Boyles) just doesn't think so.

And yet, just last week, OWASA wrote to the towns, "We believe there is little risk of running out of water this year, but the community could face a substantially more serious shortage next year, when it will be too late to catch up, if rainfall and streamflow are less than normal this winter."

See page 5 of this letter for a chart of what is and is not allowed at the various stages of water restriction. If OWASA is saying that there will be a serious shortage next year if there is less than normal rainfall this winter, and if the state climatologist is predicting a dry winter, why are we allowing up to 1,000 gallons per day of outdoor irrigation (for those on irrigation meters)?

Last weekend I sent an email to all elected officials in Chapel Hill and Carrboro asking that they request a change in the irrigation restrictions effective immediately. Last night Carrboro asked citizens to voluntarily cut back to 500 gallons and also agreed to contact Chapel Hill and OWASA for tightening the current guidelines: "The board voted to pass a resolution asking its residents to cut back to 500 gallons a day, and agreed that Chilton should contact Mayor Kevin Foy in Chapel Hill and ask that he present the same idea to the Chapel Hill Town Council and that he contact OWASA officials to say the aldermen are strongly in favor of tighter restrictions." (Chapel Hill Herald, October 3, 2007)

OWASA, as a non-profit organization, needs to collect sufficient revenues to pay their costs, even during a drought. Continuing to allow irrigation, especially with their new cost structure, passes the extra financial burden of conservation onto those who abuse the community good. But the long-term risk associated with drought, leaves me to believe the greater community good would be better served through a cost recovery mechanism that does not involve wasting a limited, precious resource.

Serious drought frequency has risen since 2000, whether we attribute it to global warming, growing populations, or changing weather patterns. We as a community need to look into new ways of protecting our water resources while also protecting the financial integrity of OWASA.