Diabetes Is a “Silent Disease”—But With Early Action, You Can Protect the Life You Want to Live

“My blood sugar was high at my health checkup, but I don’t have any symptoms…”

“I was told I have diabetes, but I’m probably still okay.”

“I’m so busy with work that I just can’t find the time to see a doctor.”

“If I start taking medication, does that mean I’ll have to take it for the rest of my life?”

“I don’t want to make my family worry about me.”

So many people have these kinds of thoughts.

As a nephrologist and dialysis physician, I have cared for many patients over the years. There have been many occasions when I have thought:

“If only they had come to see us earlier, perhaps their disease would not have progressed this far.”

Like kidney disease, diabetes often causes few or no symptoms in its early stages.

That is exactly why it is so important to take that first step when you become aware of a problem.

In this article, I would like to explain diabetes in as clear and practical a way as possible. I will cover the importance of treatment, what can happen when diabetes progresses, what you can do in your daily life, practical approaches to diet and exercise, medications, and how we can support you at our clinic.

I hope this article will give you the opportunity to think:

“There are things I can start doing.”

and

“I don’t have to deal with this alone.”

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What exactly is diabetes? Let me explain in a little more detail.

Diabetes is a disease in which the level of glucose (blood sugar) in the blood remains chronically elevated.

Our bodies use the carbohydrates and sugars we obtain from food as a source of energy. A hormone called insulin plays a central role in helping glucose move from the blood into our cells and tissues, where it can be used for energy.

When insulin does not work properly or when the body does not produce enough insulin, blood glucose cannot be lowered adequately, causing glucose to accumulate in the bloodstream.

Most people with diabetes in Japan have type 2 diabetes.

Type 2 diabetes develops through a combination of genetic predisposition and factors such as overeating, physical inactivity, obesity, stress, and aging.

However, there is no need to simply accept diabetes as something that is unavoidable because of your “constitution.”

Improving lifestyle habits can lead to significant improvements in blood glucose levels.

In contrast, type 1 diabetes is primarily an autoimmune disease in which the insulin-producing cells in the pancreas are destroyed.

It is more common in children and younger people, but it can also develop in adulthood.

There are also other forms of diabetes, including diabetes associated with pancreatic diseases, medications, and gestational diabetes, which develops during pregnancy.

When high blood glucose persists, it gradually damages blood vessels and nerves throughout the body, eventually causing a variety of complications.

That is what makes diabetes particularly concerning.

It is not simply a matter of having “high blood sugar.”

On the other hand, this also means that proper blood glucose management can significantly reduce the risk of complications.

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Why is treatment so important? Why “I feel fine right now” can be misleading

The goal of diabetes treatment is not simply to lower your blood glucose.

The ultimate goal is:

to prevent complications and maintain a life expectancy and quality of life that are as close as possible to those of people without diabetes.

It is extremely important to manage not only blood glucose, but also:

• Blood pressure

• Lipids, including cholesterol and triglycerides

• Body weight

• Smoking

The idea that we only need to focus on blood glucose is becoming outdated.

Modern diabetes treatment places much greater emphasis on protecting the kidneys and heart.

With appropriate management from an early stage, we can significantly reduce the risk of:

• Kidney disease

• Vision loss

• Numbness and difficulty healing wounds in the feet

• Myocardial infarction

• Stroke

Conversely, if diabetes is left untreated, it can progress silently, and by the time you notice something is wrong, you may already face significant limitations in your daily life.

The kidneys are particularly difficult because kidney disease often causes very few symptoms.

Even when protein begins to appear in the urine, most people do not notice anything themselves.

Our clinic specializes in nephrology, and diabetes has a profound impact on kidney health.

That is why we believe that managing blood glucose and kidney function together is one of our major strengths.

While you are thinking,

“I don’t have any symptoms, so I’m probably okay,”

changes may already be progressing inside your body.

But if you start taking action now, it is not too late.

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What happens when diabetes becomes more advanced?

Let’s take a closer look at the major complications of diabetes.

I will explain each one as clearly as possible.

1. Diabetic kidney disease

Diabetes damages the small blood vessels within the kidneys.

Albumin, a type of protein, begins to leak into the urine, and kidney function may gradually decline.

Eventually, some patients may require dialysis.

In Japan, diabetes remains one of the leading causes of patients starting dialysis.

In the early stages, there are often no symptoms at all.

The condition may not be detected unless urinary albumin is specifically measured.

At our clinic, we regularly check urinary albumin.

If diabetic kidney disease is detected early and treatment is intensified appropriately, the progression of kidney disease can often be significantly slowed.

In recent years, medications such as SGLT2 inhibitors, finerenone, and GLP-1 receptor agonists have provided additional options for protecting the kidneys.

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2. Diabetic retinopathy

Diabetes can damage the blood vessels in the retina, leading to impaired vision and, in severe cases, blindness.

There may be no symptoms during the early stages.

For this reason, regular ophthalmologic examinations are essential.

Good blood glucose control can significantly slow the progression of diabetic retinopathy.

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3. Diabetic neuropathy

Diabetic nerve damage can cause:

• Numbness in the feet

• Pain

• Reduced sensation

• Dizziness when standing

• Stomach discomfort

• Constipation or diarrhea

• Problems with urination

• Erectile dysfunction

When sensation becomes impaired, you may not notice an injury to your foot.

This can eventually lead to serious foot problems.

If you experience symptoms such as:

“It feels like I’m always wearing socks even when I’m barefoot.”

or

“My feet hurt at night.”

please consult a doctor at an early stage.

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4. Macrovascular complications: heart attack, stroke, and peripheral arterial disease

Diabetes can increase the risk of narrowing or blockage of the blood vessels supplying the:

• Heart

• Brain

• Legs

This can lead to myocardial infarction, stroke, and peripheral arterial disease.

The risk can be significantly reduced by managing not only blood glucose, but also blood pressure and cholesterol levels.

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5. Diabetic foot disease

When diabetic neuropathy and impaired blood flow occur together, people are more likely to develop:

• Foot ulcers

• Infection

• Gangrene

In severe cases, amputation may become necessary.

Daily foot inspection is extremely important.

Paying a little extra attention when trimming your toenails or choosing shoes can help prevent serious complications.

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6. Other complications and associated conditions

Diabetes may also be associated with:

• Increased susceptibility to infections

• Weaker bones

• Increased risk of cognitive impairment and dementia

• A modestly increased risk of certain cancers

• Increased risk of heart failure

• Worsening periodontal disease

In older adults, diabetes can also contribute to frailty and sarcopenia, a reduction in muscle mass and strength.

When diabetes becomes advanced, your life can change significantly.

Some people worry:

“If I need dialysis, will I still be able to work?”

“Will I still be able to travel?”

“Will I become a burden on my family?”

However,

with appropriate management from an early stage, we can significantly reduce the likelihood of reaching these situations.

In fact, many people who continue their treatment successfully are able to work, travel, pursue hobbies, and enjoy their lives normally.

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Dietary management for diabetes

— Not “restriction,” but making healthier choices —

Dietary management is one of the foundations of diabetes treatment.

However, diabetes care is no longer simply about imposing strict rules such as:

“You must never eat this.”

A more positive approach is to support you in making healthier choices that fit your lifestyle.

Estimating your energy requirements

A general approach is to determine an appropriate target body weight and then adjust calorie intake according to your level of physical activity.

A commonly used target body weight is approximately:

• Adults under 65 years: Height (m)² × 22

• Older adults: Height (m)² × 22–25, adjusted according to frailty and muscle mass

Depending on activity level, approximately 25–35 kcal/kg/day may be used as a general reference.

For people who are overweight or obese, even a weight reduction of approximately 5% can often lead to meaningful improvements in blood glucose control.

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Important considerations for older adults

For older adults, preventing malnutrition and loss of muscle mass (sarcopenia) is extremely important.

Protein intake of approximately 1.0–1.2 g/kg of actual body weight per day may be used as a general guide, with adjustments according to the individual's nutritional status and kidney function.

It is important not to reduce carbohydrates excessively.

The idea that:

“The thinner I become, the healthier I am.”

can actually be harmful in some older adults.

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Practical dietary tips

Consider the following:

• Choose lower-glycemic-index foods that cause a slower rise in blood glucose, such as brown rice and whole grains, and consider eating vegetables before carbohydrate-rich foods

• Increase dietary fiber through vegetables, seaweed, mushrooms, and legumes

• Limit salt intake, particularly to help protect your blood pressure and kidneys; aiming for less than approximately 6 g of salt per day is a useful goal

• Reduce snacks and avoid eating late at night

• Do not aim for perfection. Start with small, realistic goals such as “I’ll focus on this one thing today.”

For example:

“Today, I’ll eat more vegetables.”

or

“I’ll reduce the amount of rice slightly and make sure I get enough protein.”

Small steps are enough.

For those who need nutritional guidance, our healthcare team can work with you to develop practical meal plans that fit your lifestyle.

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Exercise therapy

— Try paying attention to your daily step count —

Exercise does more than lower blood glucose.

It can also improve:

• Blood pressure

• Lipid levels

• Cardiovascular fitness

• Muscle strength

• Mood and mental well-being

Thinking,

“I have to exercise,”

can make it feel like a difficult task.

But simply increasing your everyday physical activity can already be beneficial.

Recommended approaches include:

Aerobic exercise

Aim for at least 150 minutes per week of moderate-intensity activity, such as brisk walking at a pace that still allows you to carry on a conversation.

Resistance exercise

Aim for 2–3 sessions per week, such as squats or heel raises that can be performed at home.

A practical approach is to start by adding approximately 2,000 steps per day to your current routine and eventually aim for around:

• 8,000 steps/day for adults

• 6,000 steps/day for older adults

Using a pedometer or smartphone app can make it easier to stay motivated.

Try to avoid sitting for long periods.

Simply standing up every 30 minutes may also have beneficial effects on post-meal blood glucose.

Light strength training while watching television can be another easy way to incorporate exercise into your daily routine.

People using insulin or certain diabetes medications need to be careful about hypoglycemia.

Please consult your doctor or healthcare team about your blood glucose level before exercise and whether you need a snack.

If you are unsure how much exercise is appropriate for you, please consult us.

We can work together to create a safe and realistic exercise plan.

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Medication therapy

— Modern diabetes medications can also protect the kidneys and heart —

If lifestyle changes alone are not enough to reach your treatment goals, medication may be recommended.

There are now many effective treatment options.

Metformin

Metformin has been used for many years and is generally well established. It may also have beneficial effects on cardiovascular outcomes and possibly certain cancer risks, although these effects vary depending on the individual.

SGLT2 inhibitors

SGLT2 inhibitors do more than lower blood glucose.

They can provide significant kidney and cardiovascular protection.

By increasing glucose excretion through the urine, they can also contribute to weight loss.

We actively consider these medications when appropriate at our clinic.

GLP-1 receptor agonists

GLP-1 receptor agonists can reduce appetite, promote weight loss, and provide cardiovascular and kidney benefits.

They are available as both injectable and oral medications, depending on the specific drug.

DPP-4 inhibitors

DPP-4 inhibitors are generally easy to use and have a relatively low risk of hypoglycemia when used appropriately.

When diabetes is accompanied by kidney disease or cardiovascular disease, early consideration of medications such as SGLT2 inhibitors and GLP-1 receptor agonists is recommended in appropriate patients.

Medication does not necessarily mean:

“I have to take it for the rest of my life.”

Depending on how your condition changes, medications may sometimes be reduced or discontinued.

On the other hand, when medication is necessary, using it appropriately at the right time is extremely important.

If you are worried about side effects, unsure how to take your medication, or concerned about interactions with other medications, please feel free to ask us.

We will explain everything carefully, one step at a time.

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Things to pay attention to in daily life

— Practical tips for self-management —

• Have regular medical checkups, including blood glucose, HbA1c, urinary albumin, kidney function, blood pressure, and lipid levels

• Make a habit of checking your body weight and blood pressure regularly

• Examine your feet every day for wounds, calluses, changes in color, or other abnormalities

• Stop smoking; smoking cessation is one of the most effective ways to protect your blood vessels throughout the body

• Get adequate sleep

• Avoid excessive stress; hobbies and adequate rest are also part of good diabetes care

Trying to do everything perfectly can make it difficult to continue.

Instead, focus on small successes:

“I walked a little more today.”

“I ate more vegetables today.”

Small, sustainable improvements add up.

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For family members

Diabetes is not only an issue for the person who has it.

Understanding and support from family members can be a powerful source of encouragement in continuing treatment.

For example:

“Let’s make some healthier meals together.”

“Let’s go for a walk together.”

Support them in whatever ways are realistic for your family.

At the same time, excessive worry or criticism can sometimes make the person feel discouraged.

A supportive attitude of:

“Let’s work on this together.”

is often ideal.

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What we can offer at our clinic

— A clinic that protects both your blood glucose and your kidneys —

Although our clinic specializes in nephrology, we also actively provide comprehensive diabetes care.

Several board-certified nephrologists are available at our clinic, allowing us to support patients as a team.

We also have a physician certified by the Japan Diabetes Society, enabling us to provide specialized care for both diabetes and kidney disease.

Our services include:

• Comprehensive management of blood glucose and kidney function

• Regular assessment of urinary protein and albumin

• Medication therapy based on the latest clinical guidelines, including active use of kidney-protective medications when appropriate

• Practical advice regarding diet and exercise

• Early detection and prevention of complications

• An ABI (ankle-brachial index) device, allowing us to assess blood flow to the legs and help detect peripheral arterial disease at an early stage

• Experienced nurses specializing in foot care, who provide careful foot assessment, care, and preventive guidance. We welcome patients who are prone to foot injuries or who already have foot problems

• Long-term support that considers future treatment options, including kidney replacement therapies such as home dialysis when appropriate

• Medical care tailored to each person's lifestyle, priorities, and goals

If you are thinking:

“I have diabetes and I’m worried about my kidneys.”

“I want to adjust my diabetes medication.”

“I’m concerned about my kidney function.”

“Something abnormal was found during my health checkup.”

“I have numbness in my feet or a wound that concerns me.”

please feel free to consult us.

Our physicians genuinely enjoy talking with patients.

We want you to feel comfortable discussing not only your medical concerns, but also your worries about everyday life and the things you hope to achieve.

Let's think together about how you can protect and continue the life that is uniquely yours.

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Finally

— Take the courage to make the first step —

Diabetes is not the end of the road.

Rather, it can be an opportunity to reconsider your health and your lifestyle.

While you are thinking,

“I’m probably still okay,”

the disease may be progressing silently inside your body.

But if you start taking action now, it is not too late.

Many people tell us after beginning treatment:

“I feel better.”

“I’m less worried about the future.”

If you have been told that something is abnormal at a health checkup, are concerned about your blood glucose, are already receiving treatment but have concerns, or have a family member with diabetes, please talk to us.

You are very welcome even if you simply want to talk and learn more.

Our clinic is located a 2-minute walk from Marunouchi Station and a 3-minute walk from Fushimi Station in Nagoya.

We operate by appointment, so please make an appointment in advance.

We are committed to supporting you so that you can continue to have your own dreams and the life you want to live.

We look forward to meeting you in the consultation room.

Wataru Ono, MD
Director
Nagoya Progress Nephrology & Dialysis Marunouchi Station Clinic