57M Metabolic syn, HTN, Knee OA 10yrs NYHA 2 sob Telangana PaJR

 

27-06-2024

THIS IS AN ONLINE E LOG BOOK TO DISCUSS OUR PATIENT'S DE-IDENTIFIED HEALTH DATA SHARED AFTER TAKING HIS SIGNED INFORMED CONSENT. HERE WE DISCUSS OUR PATIENT'S PROBLEMS THROUGH SERIES OF INPUTS FROM AVAILABLE GLOBAL ONLINE COMMUNITY EXPERTS WITH AN AIM TO SOLVE THOSE PATIENT'S CLINICAL PROBLEMS WITH COLLECTIVE CURRENT BEST EVIDENCE BASED INPUTS.

[18-07-2025 15.15] PPM 1: Reviewing him now in afternoon IP rounds 

Disappeared quickly after delivering these Srisailam prasadam.

Didn't want to be examined now as he was scared that his upcoming trip to Pashupatinath may get blocked with worry if we found something!

[09-09-2025 12:21] PPM 1: Reviewing him now again in OPD with all reports post Srisailam trip:

Creatinine 1.8 mg

Can high creatinine be a function of a person's muscle mass and needs to be corrected for it accordingly? For example what is the expected creatinine of Arnold Schwarzenegger when he was doing Terminator 1 as per his muscle mass at that time? @Meta AI @PPM3

ECG shows LVH @CR do we have his previous case report link showing his previous echocardiography video?

USG is showing fatty liver as expensive

[09-09-2025 12:21] Meta AI: Yes, elevated creatinine can indeed correlate with a person's muscle mass, as muscle metabolism naturally produces creatinine. In individuals with significant muscle mass, such as professional bodybuilders or athletes, higher creatinine levels are often observed and may not necessarily indicate kidney dysfunction. Creatinine levels can be influenced by age, diet, hydration status, and muscle mass. For someone like Arnold Schwarzenegger during his "Terminator 1" era, his creatinine levels would likely have been higher than average due to his exceptional muscle mass and protein-rich diet. However, estimating his exact creatinine would require factoring in his body composition, dietary habits, and renal function at the time.¹ ² ³

Regarding the ECG showing LVH, this suggests left ventricular hypertrophy, which could be due to hypertension, increased workload on the heart, or other conditions. For the echocardiography video, check if the case report link is accessible in your hospital's electronic records system or PACS database under the patient ID.

As for the USG findings, fatty liver can be linked to lifestyle factors like diet, obesity, or metabolic syndrome. If labeled "expensive," it might indicate advanced fatty infiltration or associated complications. Was there any specific context provided for the term "expensive" in the report?

[09-09-2025 12:21] Meta AI: https://kellypicard.com/are-creatinine-and-cystatin-c-markers-of-muscle-mass/

[09-09-2025 12:21] Meta AI: https://thefitnessblogger.com/do-bodybuilders-have-higher-creatinine-levels/

[09-09-2025 12:21] Meta AI: https://cyvigor.com/article/can-high-muscle-mass-cause-high-creatinine

[09-09-2025 12:28] PPM 1: @Meta AI is there a nomogram or formula to calculate the expected serum creatinine from a person's estimated muscle mass or even body surface area?

[09-09-2025 12:28] Meta AI: There isn't a universally accepted nomogram or formula specifically to calculate expected serum creatinine directly from muscle mass or body surface area (BSA). However, some equations and models indirectly account for these factors when estimating kidney function or interpreting creatinine levels. Here are a few points to consider:

1. Creatinine Generation and Muscle Mass: Creatinine is a byproduct of creatine metabolism in muscles, so its production scales with muscle mass. While there's no direct formula to calculate creatinine from muscle mass, studies suggest that individuals with higher lean body mass will have proportionally higher baseline creatinine levels.

2. Body Surface Area (BSA): BSA is often used in equations like the Cockcroft-Gault formula or the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to estimate glomerular filtration rate (GFR). These equations adjust for age, weight, and sex, which indirectly account for muscle mass. However, they don't explicitly calculate expected creatinine for a given BSA or muscle mass.

3. Nomograms/Tools:

    - One approach is to use creatinine production rates derived from lean body mass. For example, studies estimate that muscle contributes about 20-25 mg of creatinine daily per kilogram of muscle mass. This can help approximate expected creatinine levels.

    - Tools like the Schwartz formula (for pediatrics) or the MDRD equation (for adults) also provide estimates of kidney function using serum creatinine and BSA but are more focused on GFR, not expected baseline creatinine.

4. Arnold Schwarzenegger Hypothetical Case: For someone with extreme muscle mass, like Arnold Schwarzenegger in his prime, the baseline creatinine could be substantially higher than the population average. However, without a specific model, it’s challenging to estimate his creatinine without knowing his exact lean body mass and renal function.

Would you like to explore how specific equations like Cockcroft-Gault or CKD-EPI work in practice?

[09-09-2025 12:35] PPM 1: @Meta AI @PPM2 @PPM4 @PPM3@PPM5 @PPM6 it may be a useful activity to devise a formula for calculating the serum creatinine from a person's muscle mass?

[09-09-2025 12:35] Meta AI: You’ve raised an interesting point about the lack of a direct formula linking muscle mass or BSA to serum creatinine levels, despite their clear physiological relationship. Developing such a formula would likely require data from extensive studies that account for variables like age, sex, ethnicity, and renal function, as these factors also influence serum creatinine.

Regarding your suggestion, creating a formula to estimate serum creatinine based on muscle mass could involve leveraging known creatinine production rates (e.g., 20-25 mg/day per kg of muscle) and integrating renal clearance rates. However, the challenge lies in accurately measuring muscle mass in clinical practice and accounting for individual variations in creatinine metabolism and clearance.

Would you like help outlining a theoretical framework for such a formula or exploring how current estimation tools could potentially be adapted?

[09-09-2025 12:43] PPM 3: Of course. This is an excellent and insightful question that gets to the very heart of how we interpret the common serum creatinine test.

The short answer is: *Yes, the relationship is well-established in principle, but creating a precise, universally applicable formula is challenging and it is not used clinically in the way one might use a nomogram for drug dosing.* Instead, we use formulas that incorporate factors like muscle mass (proxied by weight, age, and sex) to remove their influence and estimate kidney function itself.

Let's break this down.

### The Core Principle: Creatinine Production vs. Excretion

*   *Production:* Creatinine is a waste product from the constant breakdown of creatine phosphate in muscle. Therefore, the rate of creatinine production is *directly proportional to an individual's total muscle mass*.

*   *Excretion:* Creatinine is cleared from the blood almost exclusively by the kidneys. If kidney function is stable, the serum creatinine level reaches a steady state where the production rate equals the excretion rate.

This means that for two people with *identical kidney function, the one with greater muscle mass will have a **higher serum creatinine* level because they are producing more creatinine.

### The Challenge of a "Muscle Mass to Creatinine" Formula

Devising a simple formula Expected SCr = f(Muscle Mass) is difficult because:

1.  *Precise Muscle Mass is Hard to Measure:* In clinical practice, we don't routinely measure exact muscle mass (e.g., via DEXA scan or MRI). We use proxies like body weight, but this includes fat, which does not produce creatinine.

2.  *The Dominant Variable is Kidney Function:* The primary reason serum creatinine (SCr) changes is due to fluctuations in kidney function (glomerular filtration rate or GFR), not muscle mass. A formula predicting SCr from muscle mass would only be valid if kidney function was known to be perfectly normal and stable.

3.  *Other Influencing Factors:* Diet (high meat intake), certain medications, and even race can slightly affect creatinine generation and secretion.

### The Clinical Solution: Estimating Kidney Function (GFR)

Instead of calculating expected creatinine from muscle mass, clinicians do the *reverse. We use the **measured serum creatinine* and plug it into formulas that *account for muscle mass* (via age, sex, and weight) to *estimate the kidney's filtration rate (eGFR)*. This eGFR tells us if the creatinine level is appropriate for that person's body habitus or if it indicates kidney impairment.

The two most common formulas are:

#### 1. Cockcroft-Gault Formula (Creatinine Clearance)

This older formula estimates creatinine clearance (CrCl), which approximates GFR.

*CrCl (mL/min) =* (140 - Age) × Weight (kg) × (0.85 if female) / (72 × SCr)

*   *How it accounts for muscle mass:* It uses Weight and Age (muscle mass decreases with age) and a correction factor for Sex (men typically have more muscle mass than women).

#### 2. CKD-EPI or MDRD Formula (Estimated GFR)

These are the modern, more accurate formulas used by labs to report eGFR.

*The CKD-EPI equation is complex but is based on:*

*   *Serum Creatinine*

*   *Age*

*   *Sex*

*   *Race* (as a proxy for observed differences in average muscle mass)

When your lab report says "eGFR >60", it is already using a formula that has effectively "corrected" your creatinine for your estimated muscle mass.

### A Theoretical "Expected Creatinine" Calculation

If we assume a normal, stable kidney function (e.g., GFR of 100 mL/min/1.73m²), we can rearrange the principles to get a rough idea.

The daily production of creatinine is relatively constant:

*   *Men:* ~20-25 mg/kg of ideal body weight per day

*   *Women:* ~15-20 mg/kg of ideal body weight per day

Since the body is in a steady state (production = excretion), and excretion is GFR × Serum Creatinine, we can estimate:

*Expected Serum Creatinine (mg/dL) ≈* Daily Creatinine Production (mg/day) / (GFR × 14.4)

The 14.4 is a conversion factor to get from mL/min to L/day.

*Example:* A 70 kg young man with an assumed normal GFR of 100 mL/min.

*   Production = 70 kg × 23 mg/kg/day = 1610 mg/day

*   Expected SCr = 1610 / (100 × 14.4) ≈ *1.12 mg/dL*

This aligns with the common clinical rule of thumb:

*   *~0.8 - 1.2 mg/dL* for healthy young men

*   *~0.6 - 0.9 mg/dL* for healthy young women

*   *Lower values* in elderly or cachexic patients due to less muscle mass.

### Conclusion and Recommendation

*   *There is no standard nomogram* to look up expected creatinine based on muscle mass because its clinical utility is limited.

*   The concept is *physiologically sound—muscle mass is the primary determinant of creatinine *production.

*   *Clinically, we work backwards.* We use the measured creatinine level and factor in age, sex, and weight to estimate kidney function (eGFR/CrCl). This effectively "normalizes" the creatinine for a person's muscle mass.

*   *The best "formula" is your lab's reported eGFR.* This number already answers the question you're getting at: "For this person's body size, age, and sex, is their creatinine level indicating good kidney function?"

Therefore, while devising such a formula is a useful thought exercise to understand renal physiology, its practical application is already embedded within the standard eGFR calculations used in everyday medicine.