At a Glance:

• Metabolic syndrome is a cluster of five abnormalities, not a single disease

• Nearly 1 in 3 Indian adults is affected; most are undiagnosed

• Indians face higher metabolic risk at lower BMI than Western populations

• All five criteria share one root mechanism: insulin resistance

• Standard annual health checks in India miss the earliest and most actionable markers

36-year-old Arjun, a software professional from a metropolitan city, eats mostly a balanced diet and exercises when he can. About a year back, he had a company health check. Three results came back abnormal: waist circumference on the higher side, borderline triglycerides, and a fasting blood glucose at the upper limit of normal. The doctor noted all three. Told him to watch what he eats.

No diagnosis was made. No one told Arjun that those three findings share a mechanism, that together, they have a name, and that name carries a specific set of clinical consequences. He left without that information.

Arjun is not alone in India today.

Arjun is a fictional composite. The clinical pattern is well-documented.

What Is Metabolic Syndrome, And Why the Term Matters

Metabolic syndrome is not a single disease. It is a cluster of five metabolic abnormalities. When three or more are present in the same individual, the risk of type 2 diabetes, cardiovascular disease, fatty liver disease, and certain cancers increases substantially. The syndrome label is clinically significant, it indicates no single cause and no single therapeutic target. But all five share a common biological driver. Identifying that driver is where clinical management begins.

One feature of metabolic syndrome is visible on examination, frequently present, and almost as frequently missed. Dark, velvety skin patches on the posterior neck, axillae, and groin, acanthosis nigricans, are not a dermatological incidental. They are a cutaneous marker of sustained hyperinsulinaemia.

A patient presenting with these patches warrants metabolic evaluation. Body weight is not a reliable exclusion criterion here.

Why Indians Are at Risk at a Lower BMI, The South Asian Paradox

Almost one in three adults in India have metabolic syndrome. Urban prevalence stands at 32%, with women showing higher rates 35%, compared to 26% in men. The more clinically important question is who, not how many.

Indians develop metabolic complications at body weights that carry no flag in Western clinical guidelines. A BMI of 23 is within the normal range by global standards. In a South Asian individual, that same BMI can coexist with substantial visceral fat accumulation, fat deposited around internal organs, metabolically active, and not reflected on a weighing scale. This is the basis for the International Diabetes Federation's lower waist circumference thresholds for South Asians: 90 cm in men and 80 cm in women, against the 102 cm and 88 cm used in Western guidelines.

The underlying mechanism is storage capacity. "Abdominal fat is not just storage, it is a marker of underlying insulin resistance," says Dr. Chandrashekar. "Indians tend to have a lower capacity to store excess energy safely in subcutaneous fat. Once this capacity is exceeded, the excess gets deposited around the abdomen and organs as visceral fat, which drives complications related to Metabolic Syndrome."

Insulin Resistance: The Biochemical Thread Connecting All Five

All five criteria of metabolic syndrome trace back to one root mechanism: insulin resistance.

Visceral fat is not metabolically inert. It releases signalling proteins, adipokines, that regulate insulin sensitivity, appetite, and inflammation. In an individual with excess visceral fat, this regulatory system becomes dysregulated. Leptin rises but loses efficacy at the receptor level. Adiponectin, which ordinarily maintains hepatic insulin sensitivity, falls. Resistin increases, promoting a state of low-grade systemic inflammation. The net effect on the liver is insulin resistance: hepatic glucose output continues despite rising insulin concentrations.

That is the root. Everything downstream is a consequence of it.

Elevated circulating glucose prompts compensatory insulin secretion from the pancreas. Sustained hyperinsulinaemia drives hepatic de novo lipogenesis, triglycerides rise, HDL falls. The same hyperinsulinaemia acts on the renal tubules to increase sodium reabsorption and activates the sympathetic nervous system. Blood pressure rises through both pathways. Five criteria. One mechanism.

A clinically important corollary: insulin resistance precedes abnormal fasting glucose by years, in some cases, a decade or more. "Someone can have dangerously high insulin levels for years before blood sugar budges," says Dr. Chandrashekar. By the time a fasting glucose is flagged on an annual health report, the underlying pathology is not new.

Insulin resistance is identified clinically in most cases. "Some of the most common findings are dark skin patches on the neck, skin tags, and a large waist," Dr. Chandrashekar notes. Fasting insulin and HOMA-IR are reserved for selected cases, lean patients with suspected insulin resistance, early PCOS, or genuine diagnostic uncertainty. They are not part of standard metabolic screening.

Reading the Five Warning Signs: What Each Number Is Telling You

The five diagnostic criteria are not arbitrary statistical cutoffs. Each reflects a specific pathophysiological event.

1. Central obesity (waist ≥90 cm men / ≥80 cm women) The most clinically significant criterion, and the most consistently absent from Indian annual health packages. A tape measure takes under a minute. Most health check panels do not include it. "Central obesity often precedes abnormalities in blood sugar and lipids, yet it is frequently ignored if overall body weight appears normal," says Dr. Chandrashekar. That gap is where diagnoses are missed.

2. High triglycerides (≥150 mg/dL) A direct downstream product of hepatic insulin resistance and excess carbohydrate substrate. Elevated triglycerides suppress HDL synthesis, which is why these two criteria co-present so reliably. One predicts the other. The triglyceride-to-HDL ratio, rarely reported on standard Indian lab panels, is among the earliest indicators of insulin resistance. (A ratio above 3.5 in a South Asian patient carries stronger predictive value for insulin resistance than fasting glucose alone.)

3. Low HDL (<40 mg/dL men / <50 mg/dL women) HDL functions as a reverse cholesterol transporter, extracting cholesterol from arterial walls and returning it to the liver for clearance. A low HDL in the context of metabolic syndrome is not simply a number below a reference range. It indicates impaired reverse cholesterol transport. The clinical consequence is accelerated atherogenesis.

4. Elevated blood pressure (≥130/85 mmHg) Two mechanisms operate simultaneously: hyperinsulinaemia-driven renal sodium retention increases circulating volume, and sympathetic nervous system activation increases vascular resistance. Both are independent of dietary sodium intake. Treating hypertension without addressing the underlying insulin excess addresses the symptom without the cause.

5. Elevated fasting glucose (≥100 mg/dL) The last criterion to become abnormal in the natural history of metabolic syndrome. Its appearance on a report does not mark the beginning of the problem, it marks the end of the compensatory phase. Insulin resistance, dyslipidaemia, and blood pressure changes typically predate this finding by years.

Three Misconceptions That Delay Diagnosis

1. "I am not overweight, so I am not at risk." 

Visceral fat accumulation occurs independently of total body weight. A lean South Asian individual can carry metabolically significant ectopic fat around internal organs with fully disrupted adipokine signalling, none of which registers on a scale or a BMI calculation.

2. "This condition affects older adults." 

Metabolic syndrome prevalence in the 18–29 age group in India is documented at 13% and is increasing in parallel with urbanisation and dietary transition. It is not a condition of middle age.

3. "This is essentially pre-diabetes." 

Pre-diabetes describes a single dysglycaemic state. Metabolic syndrome simultaneously elevates cardiovascular, hepatic, and oncological risk through three partially independent biological pathways. Addressing glycaemia alone, while dyslipidaemia, hypertension, and central adiposity remain unmanaged, constitutes incomplete clinical care.

References

1. Hirode G, Wong RJ. Prevalence of metabolic syndrome among adult population in India. PLOS ONE. 2020;15(10). PMC7571716.

2. Bidhu RP, et al. Prevalence and Determinants of Metabolic Syndrome Among Adults in Urban and Rural South India. Cureus. 2025. PMC12178443.

3. International Diabetes Federation. IDF Consensus Worldwide Definition of the Metabolic Syndrome. 2006.

4. Alberti KGMM, et al. Harmonizing the Metabolic Syndrome. Circulation. 2009.